To increase the resilience of farmers’livelihood systems,detailed knowledge of adaptation strategies for dealing with the impacts of climate change is required.Knowledge co-production approach is an adaptation strate...To increase the resilience of farmers’livelihood systems,detailed knowledge of adaptation strategies for dealing with the impacts of climate change is required.Knowledge co-production approach is an adaptation strategy that is considered appropriate in the context of the increasing frequency of disasters caused by climate change.Previous research of knowledge co-production on climate change adaptation in Indonesia is insufficient,particularly at local level,so we examined the flow of climate change adaptation knowledge in the knowledge co-production process through climate field school(CFS)activities in this study.We interviewed 120 people living in Bulukumba Regency,South Sulawesi Province,Indonesia,involving 12 crowds including male and female farmers participated in CFS and not participated in CFS,local government officials,agriculture extension workers,agricultural traders,farmers’family members and neighbors,etc.In brief,the 12 groups of people mainly include two categories of people,i.e.,people involved in CFS activities and outside CFS.We applied descriptive method and Social network analysis(SNA)to determine how knowledge flow in the community network and which groups of actors are important for knowledge flow.The findings of this study reveal that participants in CFS activities convey the knowledge they acquired formally(i.e.,from TV,radio,government,etc.)and informally(i.e.,from market,friends,relatives,etc.)to other actors,especially to their families and neighbors.The results also show that the acquisition and sharing of knowledge facilitate the flow of climate change adaptation knowledge based on knowledge co-operation.In addition,the findings highlight the key role of actors in the knowledge transfer process,and key actors involved in disseminating information about climate change adaptation.To be specific,among all the actors,family member and neighbor of CFS actor are the most common actors in disseminating climate knowledge information and closest to other actors in the network;agricultural trader and family member of CFS actor collaborate most with other actors in the community network;and farmers participated in CFS,including those heads of farmer groups,agricultural extension workers,and local government officials are more willing to contact with other actors in the network.To facilitate the flow of knowledge on climate change adaptation,CFS activities should be conducted regularly and CFS models that fit the situation of farmers’vulnerability to climate change should be developed.展开更多
The reduction behaviors of FeO·V2O3 and FeO·Cr2O3 during coal-based direct reduction have a decisive impact on the efficient utilization of high-chromium vanadium-bearing titanomagnetite concentrates. The ef...The reduction behaviors of FeO·V2O3 and FeO·Cr2O3 during coal-based direct reduction have a decisive impact on the efficient utilization of high-chromium vanadium-bearing titanomagnetite concentrates. The effects of molar ratio of C to Fe n(C)/n(Fe) and temperature on the behaviors of vanadium and chromium during direct reduction and magnetic separation were investigated. The reduced samples were characterized by X-ray diffraction(XRD), scanning election microscopy(SEM) and energy dispersive spectrometry(EDS) techniques. Experimental results indicate that the recoveries of vanadium and chromium rapidly increase from 10.0% and 9.6% to 45.3% and 74.3%, respectively, as the n(C)/n(Fe) increases from 0.8 to 1.4. At n(C)/n(Fe) of 0.8, the recoveries of vanadium and chromium are always lower than 10.0% in the whole temperature range of 1100-1250 °C. However, at n(C)/n(Fe) of 1.2, the recoveries of vanadium and chromium considerably increase from 17.8% and 33.8% to 42.4% and 76.0%, respectively, as the temperature increases from 1100 °C to 1250 °C. At n(C)/n(Fe) lower than 0.8, most of the FeO·V2O3 and FeO·Cr2O3 are not reduced to carbides because of the lack of carbonaceous reductants, and the temperature has little effect on the reduction behaviors of FeO·V2O3 and FeO·Cr2O3, resulting in very low recoveries of vanadium and chromium during magnetic separation. However, at higher n(C)/n(Fe), the reduction rates of FeO·V2O3 and FeO·Cr2O3 increase significatly because of the excess amount of carbonaceous reductants. Moreover, higher temperatures largely induce the reduction of FeO·V2O3 and FeO·Cr2O3 to carbides. The newly formed carbides are then dissolved in the γ(FCC) phase, and recovered accompanied with the metallic iron during magnetic separation.展开更多
A low-grade nickel laterite ore was reduced at different reduction temperatures. The morphology of metallic particles was investigated by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS)...A low-grade nickel laterite ore was reduced at different reduction temperatures. The morphology of metallic particles was investigated by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). Experimental results indicate that the metallic nickel and iron gradually assemble and grow into larger spherical particles with increasing temperature and prolonging time. After reduction, the nickel laterite ore obviously changes into two parts of Fe-Ni metallic particles and slag matrix. An obvious relationship is found between the reduction of iron magnesium olivine and its crystal chemical properties. The nickel and iron oxides are reduced to metallic by reductant, and the lattice of olivine is destroyed. The entire reduction process is comprised of oxide reduction and metallic phase growth.展开更多
Zeolite derived from coal-based solid wastes(coal gangue and coal fly ash)can overcome the environmental problems caused by coal-based solid wastes and achieve valuable utilization.In this paper,the physicochemical pr...Zeolite derived from coal-based solid wastes(coal gangue and coal fly ash)can overcome the environmental problems caused by coal-based solid wastes and achieve valuable utilization.In this paper,the physicochemical properties of coal gangue and coal fly ash are introduced.The mechanism and application characteristics of the pretreatment processes for zeolite synthesis from coal-based solid wastes are also introduced.The synthesis processes of coal-based solid waste zeolite and their advantages and disadvantages are summarized.Furthermore,the application characteristics of various coal-based solid waste zeolites and their common application fields are illustrated.Finally,we propose an alkaline fusion-assisted supercritical hydrothermal crystallization as an efficient method for synthesizing coal-based solid waste zeolites.In addition,more attention should be given to the recycling of alkaline waste liquid and the application of coal-based solid waste zeolites in the field of volatile organic compound adsorption removal.展开更多
To understand the migration mechanisms of phosphorus(P)during coal-based reduction,a high-phosphorus oolitic iron ore was reduced by coal under various experimental conditions.The migration characteristics and kinetic...To understand the migration mechanisms of phosphorus(P)during coal-based reduction,a high-phosphorus oolitic iron ore was reduced by coal under various experimental conditions.The migration characteristics and kinetics of P were investigated by a field-emission electron probe microanalyzer(FE-EPMA)and using the basic principle of solid phase mass transfer,respectively.Experimental results showed that the P transferred from the slag to the metallic phase during reduction,and the migration process could be divided into three stages:phosphorus diffusing from the slag to the metallic interface,the formation of Fe P compounds at the slag metal interface and P diffusing from the slag metal interface to the metallic interior.The reduction time and temperature significantly influenced the phosphorus content of the metallic and slag phases.The P content of the metallic phase increased with increasing reduction time and temperature,while that of the slag phase gradually decreased.The P diffusion constant and activation energy were determined and a migration kinetics model of P in coal-based reduction was proposed.P diffusion in the metallic phase was the controlling step of the P migration.展开更多
NaY zeolites were in-situ synthesized from coal-based kaolin via thehydrothermal method. The effects of various factors on the structure of the samples were extensivelyinvestigated. The samples were characterized by N...NaY zeolites were in-situ synthesized from coal-based kaolin via thehydrothermal method. The effects of various factors on the structure of the samples were extensivelyinvestigated. The samples were characterized by N_2 adsorption, XRD, IR and DTG-DTA methods, andthe results show that the crystallization temperature and amount of added water play an importantrole in the formation of the zeolite structure. The 4A and P zeolites are the competitive phasepresent in the resulting product. However, NaY zeolites with a higher relative crystallinity,excluding impure crystals and the well hydrothermal stability, can be synthesized from coal-basedkaolin. These zeolites possess a larger surface area and a narrow pore size distribution, and thismeans that optimization of this process might result in a commercial route to synthesize NaYzeolites from coal-based kaolin.展开更多
The intrinsic kinetic models of the Langmuir-Hinshelwood type were investigated in terms of the reaction rates of CO hydrogenation and CO_2 hydrogenation in theform of reactant fugacity. The parameters were estimated ...The intrinsic kinetic models of the Langmuir-Hinshelwood type were investigated in terms of the reaction rates of CO hydrogenation and CO_2 hydrogenation in theform of reactant fugacity. The parameters were estimated by the Universal Global Optimization using the Marquardt method. Residual error distribution and statistic tests show thatthe intrinsic kinetic models are reliable and acceptable. The mathematic model of a combined converter formed by gas-cooled and water-cooled reactor was developed and thegas-cooled reactor and the water-cooled reactor were characterized with one-dimensionalmathematic model. The distributions of temperature and concentration in the catalytic bedof the gas-cooled reactor and the water-cooled reactor in a combined converter with ayield of 1.2 Mt/a were simulated. The parallel cross linking pore model was used to describe the transfer process of multi-component diffusion system in the catalyst. The calculated value computed by the internal diffusion efficiency factor calculation model established for methanol synthesis catalyst fit the experimental value very well.展开更多
In this study,the Heishan coal was used to prepare a series of activated carbon(AC)samples via a vapor deposition method.The effects of the Fe(NO_(3))3/coal weight ratio on the physicochemical properties of the activa...In this study,the Heishan coal was used to prepare a series of activated carbon(AC)samples via a vapor deposition method.The effects of the Fe(NO_(3))3/coal weight ratio on the physicochemical properties of the activated carbon were systematically investigated,and the AC samples were analyzed by the N2 adsorption-desorption technique,the scanning electron microscopy,the X-ray diffraction,the Raman spectroscopy,and the Fourier transform infrared spectroscopy.Furthermore,the adsorption properties of ethyl acetate were investigated.The results indicated that as the Fe(NO_(3))3/coal mass ratio increased from 1:8 to 1:2,the specific surface area,the total pore volume and the micropore volume initially increased and then decreased.The specific surface area increased from 560.86 m^(2)/g to 685.90 m^(2)/g,and then decreased to 299.56 m^(2)/g.The total pore volume and micropore volume increased from 0.29 cm^(3)/g and 0.17 cm^(3)/g to 0.30 cm^(3)/g and 0.22 cm^(3)/g,and then decreased to 0.16 cm^(3)/g and 0.10 cm^(3)/g,respectively.The optimized ratio was 1:8.During the activation process,iron ions infiltrated the activated carbon to promote the development of the pore structure,the pore size of which was between 2.5 nm and 3 nm in daimeter.This approach could enhance the capacity for adsorption of ethyl acetate.It is worth noting that the ACs displaying the largest specific surface area and total pore volume(685.90 m^(2)/g and 0.30 cm^(3)/g)were formed under the optimized activation conditions(950℃,20%(volume)of CO_(2),ratio 1:5),and the maximum AC capacity for adsorption of ethyl acetate was 962.62 mg/g.After seven repeated thermal regeneration experiments,the saturated AC adsorption capacity was still above 90%.展开更多
Beach titanomagnetite(TTM)provides a cheap alternative source of Fe and Ti,but this ore is difficult to process to make suitable concentrates for the blast furnace.Recently studies showed that it is feasible to separa...Beach titanomagnetite(TTM)provides a cheap alternative source of Fe and Ti,but this ore is difficult to process to make suitable concentrates for the blast furnace.Recently studies showed that it is feasible to separate Fe and Ti by coal-based direct reduction.In this study,beach TTM was selected as the research object,the effects of reducing agents on reducing atmosphere in coal-based direct reduction of beach TTM were analyzed,and the role of volatiles was also studied.The results showed that when bitumite and coke were used as reducing agents of TTM,the CO produced from volatiles was involved in the reduction reaction,and the generated CO_(2) provided the raw material for the reaction of TTM.The reduction effect of bitumite was better than that of coke.The reason is that bitumite+TTM had a higher gas generation rate and produced a higher CO partial pressure,while coke+TTM had a lower gas generation rate and produced a lower CO partial pressure.When graphite was used as a reducing agent,there was a solid-solid reaction in the early stage in the reaction.With the continuous accumulation of CO_(2),the Boudouad reaction started and accelerated.Graphite+TTM also produced a higher CO partial pressure.展开更多
A process of purification of coal-based coke powder as anode the treatment of coke powder with dilute hydrofluoric acid solution, for Li-ion batteries was attempted. The process started with followed by united-acid-le...A process of purification of coal-based coke powder as anode the treatment of coke powder with dilute hydrofluoric acid solution, for Li-ion batteries was attempted. The process started with followed by united-acid-leaching using sulfuric acid and hydrochloric acid. The effects of altering the hydrofluoric acid addition, hydrofluoric acid concentration, contact time, temperature and acid type were investigated. A minimum ash content of 0.35% was obtained when proper conditions were applied. The electrochemical performance of purified coke powder shows greatly improved electrochemical performance. The as-purified coke powder presented an initial reversible capacity of 257.4 mAh/g and a retention rate of 95% after 50 cycles. The proposed purification process paves a way to prepare a promising anode material with good performance with low cost of coke powder for Li-ion batteries.展开更多
The role of Nil(NO3)2 in the preparation of a magnetic activated carbon is reported in this paper. Magnetic coal-based activated carbons (MCAC) were prepared from Taixi anthracite with low ash content in the prese...The role of Nil(NO3)2 in the preparation of a magnetic activated carbon is reported in this paper. Magnetic coal-based activated carbons (MCAC) were prepared from Taixi anthracite with low ash content in the presence of Ni(NO3)2. The MCAC materials were characterized by a vibrating sample magnetometer (VSM), X-ray diffraction (XRD), a scanning electric microscope (SEM), and by N2 adsorption. The cylindri- cal precursors and derived char were also subjected to thermogravimetric analysis to compare their behavior of weight losses during carbonization. The results show that MCAC has a larger surface area (1074 m21g) and a higher pore volume (0.5792 cm3/g) with enhanced mesopore ratio (by about 10~). It also has a high saturation magnetization (1.6749 emu/g) and low coercivity (43.26 Oe), which allows the material to be magnetically separated. The MCAC is easily magnetized because the nickel salt is con- vetted into Ni during carbonization and activation. Metallic Ni has a strong magnetism on account of electrostatic interaction. Added Ni(NO3)2 catalyzes the carbonization and activation process by accelerat- ing burn off of the carbon, which contributes to the development of mesopores and macropores in the activated carbon.展开更多
The application of coal-based reduction in the efficient recovery of iron from refractory iron-bearing resources is comprehensively reviewed.Currently,the development and beneficiation of refractory iron-bearing resou...The application of coal-based reduction in the efficient recovery of iron from refractory iron-bearing resources is comprehensively reviewed.Currently,the development and beneficiation of refractory iron-bearing resources have attracted increasing attention.However,the effect of iron recovery by traditional beneficiation methods is unacceptable.Coal-based reduction followed by magnetic separation is proposed,which adopts coal as the reductant to reduce iron oxides to metallic iron below the melting temperature.The metallic iron particles aggregate and grow,and the particle size continuously increases to be suitable for magnetic separation.The optimization and application of coal-based reduction have been abundantly researched.A detailed literature study on coal-based reduction is performed from the perspectives of thermodynamics,reduction kinetics,growth of metallic iron particles,additives,and application.The coal-based reduction industrial equipment can be developed based on the existing pyrometallurgical equipments,rotary hearth furnace and rotary kiln,which are introduced briefly.However,coal-based reduction currently mainly adopts coal as a reductant and fuel,which may result in high levels of carbon dioxide emissions,energy consumption,and pollution.Technological innovation aiming at decreasing carbon dioxide emissions is a new trend of green and sustainable development of the steel industry.Therefore,the substitution of coal with clean energy(hydrogen,biomass,etc.)for iron oxide reduction shows promise in the future.展开更多
Based on the process of coal-based self-reduction and melting separation at high temperature, it was investigated that the effect of process factors on the reduction of iron and nickel oxide, the metal yield and the n...Based on the process of coal-based self-reduction and melting separation at high temperature, it was investigated that the effect of process factors on the reduction of iron and nickel oxide, the metal yield and the nickel content in ferronickel about the laterite nickel ore, was from Philippines and contented low nickel, high iron and aluminum. The results showed that if the C/O mole ratio was not higher than 0.5 and the reduction temperature was kept as 1200°C and then increased up to 1500°C, the metal could not separate from molten slag for the A series of experiments, which were only added CaF<sub>2</sub>. However, when the C/O ratio was added up to 0.6 - 0.8, the metal could separate well from the slag, and the yields of Fe and Ni increased gradually. But the nickel content in the metal declined from 1.79% to 1.34%. When the C/O ratio increased to 1.2, and the temperature of melting products obtained at 1200°C and rose to 1550°C, the separation of metal from slag could not be realized in B group of tests, which were only added hydrated lime. However, when both of CaF<sub>2</sub> and hydrated lime were added, the metal could separate from slag in C group. In order to increase the content of nickel in the metal, it is necessary to restrain the reduction of iron oxide. When the C/O mole ratio is 0.6, the nickel content of metal could be 1.79%, which was higher than the theoretical ratio 1.65% of Ni/(Ni + Fe) of the latcritic nickel ore, but the yield of nickle was only 71.3%.展开更多
Solid wastes derived from metallurgical industries pose a significant threat to environment. The utilization and disposal of these solid wastes are the major concern in the world. Semi-coke generated in coal-based dir...Solid wastes derived from metallurgical industries pose a significant threat to environment. The utilization and disposal of these solid wastes are the major concern in the world. Semi-coke generated in coal-based direct reduction process of iron ore is a by-product and its suitable utilization is not available so far. In order to handle it properly, the characteristics of this by-product were comprehensively investigated. A series of analysis methods were used to demonstrate its mineral compositions, petrography and physico-chemical properties. The results reveal that the semi-coke has poor washability. The fixed carbon content of semi-coke reaches 76.11% and the gross calorific value is 28.10 MJ/kg, both of which are similar to those of traditional sinter coke breeze. Also, semi-coke ash possesses lower content of SiO2, Al2O3, S and higher content of CaO and MgO, which could improve the strength of sinter ore when partially substituting for coke breeze in sintering. Semi-coke features well-development porous structure and higher reaction activity, which predicts that the sintering speed could be elevated to some extent when employing it as a partial replacement of coke breeze, so the studies further suggest that the potential adverse effect of the high reactivity on sintering process could be weakened by adequately coarsening the semi-coke's particle size.展开更多
Mathematical simulation was performed on tube-shell reactor for dimethyl ether (DME) synthesis from coal-based syngas. The model was established based on kinetics of dimethyl-ether synthesis from syngas over a bifun...Mathematical simulation was performed on tube-shell reactor for dimethyl ether (DME) synthesis from coal-based syngas. The model was established based on kinetics of dimethyl-ether synthesis from syngas over a bifunctional catalyst, which is mixed by methanol synthesis catalyst and dehydration catalyst as 1:1 mass ratio. Methanol synthesis from CO and CO2 and methanol dehydration were selected as three-independent reactions, CO, CO2, and DME as key components to estab- lish the one-dimensional mathematical model of the reactor. The gas concentration and temperature profiles inside the reactor tubes were obtained. The operating conditions affecting DME synthesis were also discussed based on the model. The simula- tions indicate that higher pressure and lower temperature at the inlet and rich hydrogen in the reactant are favorable in direct DME synthesis in fixed-bed process, and the temperature of boiling water affect the reactor performance seriously.展开更多
Efficient detection of coalbed methane(CBM) co-production interference is the key to timely adjusting the development plan and improving the co-production efficiency. Based on production data of six typical CBM co-pro...Efficient detection of coalbed methane(CBM) co-production interference is the key to timely adjusting the development plan and improving the co-production efficiency. Based on production data of six typical CBM co-production wells in the Zhijin block of western Guizhou Province, China, the production characteristic curves, including production indication curve, curve of daily water production per unit drawdown of producing fluid level with time, and curve of water production per unit differential pressure with time have been analyzed to explore the response characteristics of co-production interference on the production characteristic curves. Based on the unit water inflow data of pumping test in coal measures, the critical value of in-situ water production of the CBM wells is 2 m^(3)/(d·m). The form and the slope of the initial linear section of the production indication curves have clear responses to the interference, which can be used to discriminate internal water source from external water source based on the critical slope value of 200 m^(3)/MPa in the initial linear section of the production indication curve. The time variation curves of water production per unit differential pressure can be divided into two morphological types: up-concave curve and down-concave curve. The former is represented by producing internal water with average daily gas production greater than 800 m^(3)/d, and the latter produces external water with average daily gas production smaller than 400 m^(3)/d. The method and critical indexes for recognition of CBM co-production interference based on the production characteristic curve are constructed. A template for discriminating interference of CBM co-production was constructed combined with the gas production efficiency analysis, which can provide reference for optimizing co-production engineering design and exploring economic and efficient co-production mode.展开更多
The application of big data technology provides support for the co-production of public safety services.Existing research often focuses on how technology influences co-production,but lacks attention to the key actors ...The application of big data technology provides support for the co-production of public safety services.Existing research often focuses on how technology influences co-production,but lacks attention to the key actors that drive co-production and the mechanisms that facilitate it.This study examines the role of government in the digital co-production of public safety services,using the practice of Shenzhen as a case study.Shenzhen has built 125 information systems based on over 100 billion pieces of big data,forming a model of digital safety service co-production.The study reveals three types of digital co-production,characterized by"government-business joint planning,passive participation of businesses and the public,and active cooperation among government,businesses,and the public"in the"design-production-application"stages.The study shows that the government is not only a co-producer but also a proactive actor in activating the willingness of non-governmental entities to participate.Local governments mobilize non-governmental participation through three mechanisms:empowerment,profit enhancement,and value co-creation.The"power-interest-value"paradigm is applicable for analyzing the co-production of public services and helps to explain the transformation mechanisms of co-production behavior.展开更多
The scalable production of high grade activated carbon from abundant coal for supercapacitors application is an efficient way to achieve high value-added utilization of coal sources.However,this technology is challeng...The scalable production of high grade activated carbon from abundant coal for supercapacitors application is an efficient way to achieve high value-added utilization of coal sources.However,this technology is challenging due to lack of comprehensive understanding on the mechanism of activation process and effect of external factors.In this paper,the effect of activating temperature and time on the specific capacitance of coal-based activated carbon prepared by H2O steam activation was studied using the response surface method.Under optimal conditions,coal-based activated carbon exhibits the largest specific capacitance of 194.35 F·g^(−1),thanks to the appropriate pore/surface structure and defect degree.Density functional theory calculations explain in detail the mechanism of contraction of aromatic rings and overflow of H2 and CO during the activation.Meanwhile,oxygen-containing functional groups are introduced,contributing to the pseudocapacitance property of coal-based activated carbon.This mechanism of reactions between aromatic carbon and H2O vapor provides understanding on the role of water during coal processing at the molecular level,offering great potential to regulate product distribution and predict rate of pore generation.This insight would contribute to the advancement of other coal processing technology such as gasification.展开更多
A novel composite photocatalyst for photocatalytic decomposition of water for hydrogen evolution was successfully synthesized by in-situ growth of nitrogen and sulfur co-doped coal-based carbon quantum dots(NSCQDs)nan...A novel composite photocatalyst for photocatalytic decomposition of water for hydrogen evolution was successfully synthesized by in-situ growth of nitrogen and sulfur co-doped coal-based carbon quantum dots(NSCQDs)nanoparticles on the surface of sheet cobalt-based metal-organic framework(Co-MOF)and graphitic carbon nitride(g-C_(3)N_(4),CN).The structure and properties of the obtained catalysts were systematically analyzed.NSCQDs effectively broaden the absorption of Co-MOF and CN in the visible region.The new composite photocatalyst has high hydrogen production activity and the hydrogen production rate reaches 6254μmol/(g·h)at pH=9.At the same time,NSCQDs synergy Co-MOF/CN composites have good stability.After four cycles of hydrogen production,the performance remains relatively stable.The tran sient photocurrent response and Nyquist plot experimental results further demonstrate the improvement of carrier separation efficiency in composite catalysts.The semiconductor type(n-type semico nductor)of the single-phase catalyst was determined by the Mott-Schottky test,and the band structure was analyzed.The conductive and valence bands of CN are-0.99 and 1.72 eV,respectively,and the conduction and valence bands of Co-MOF are-1.85 and 1.33 eV,respectively.Th e mechanism of the photocatalytic reaction can be inferred,that is,Z-type heterojunction is formed between CN an d Co-MOF,and NSCQDs was used as cocatalyst.展开更多
Single-atom photocatalysts(SAPCs)have attracted great interests due to their remarkable atom utilization efficiency,excellent activity,and selectivity,yet no application in synchronous biorefinery and water splitting....Single-atom photocatalysts(SAPCs)have attracted great interests due to their remarkable atom utilization efficiency,excellent activity,and selectivity,yet no application in synchronous biorefinery and water splitting.Here,efficient SAPCs based on atomically dispersed Zn atoms on carbon nitride(named Zn-mCN)were produced.Experiments verified that Zn-mCN has widened adsorption range of visible-light and lowered ability of electron-hole recombination,leading to excellent photocatalytic redox activity for synchronous biorefinery and water splitting to co-produce lactic acid(selectivity up to 91.0%)and hydrogen(-15898.8μmolg^(-1)h^(-1)).This system has excellent universality for small-molecule monosaccharides and macromolecular xylan.Poisoning experiments showed that h^(+),1O2,·O_(2)-and·OH can promote the simultaneous production of lactic acid and hydrogen.This work realized full utilization of whole redox reaction and provided a novel strategy for efficient and concomitant production of hydrogen and value-added chemicals from biomass-derived feedstocks aqueous solutions.展开更多
文摘To increase the resilience of farmers’livelihood systems,detailed knowledge of adaptation strategies for dealing with the impacts of climate change is required.Knowledge co-production approach is an adaptation strategy that is considered appropriate in the context of the increasing frequency of disasters caused by climate change.Previous research of knowledge co-production on climate change adaptation in Indonesia is insufficient,particularly at local level,so we examined the flow of climate change adaptation knowledge in the knowledge co-production process through climate field school(CFS)activities in this study.We interviewed 120 people living in Bulukumba Regency,South Sulawesi Province,Indonesia,involving 12 crowds including male and female farmers participated in CFS and not participated in CFS,local government officials,agriculture extension workers,agricultural traders,farmers’family members and neighbors,etc.In brief,the 12 groups of people mainly include two categories of people,i.e.,people involved in CFS activities and outside CFS.We applied descriptive method and Social network analysis(SNA)to determine how knowledge flow in the community network and which groups of actors are important for knowledge flow.The findings of this study reveal that participants in CFS activities convey the knowledge they acquired formally(i.e.,from TV,radio,government,etc.)and informally(i.e.,from market,friends,relatives,etc.)to other actors,especially to their families and neighbors.The results also show that the acquisition and sharing of knowledge facilitate the flow of climate change adaptation knowledge based on knowledge co-operation.In addition,the findings highlight the key role of actors in the knowledge transfer process,and key actors involved in disseminating information about climate change adaptation.To be specific,among all the actors,family member and neighbor of CFS actor are the most common actors in disseminating climate knowledge information and closest to other actors in the network;agricultural trader and family member of CFS actor collaborate most with other actors in the community network;and farmers participated in CFS,including those heads of farmer groups,agricultural extension workers,and local government officials are more willing to contact with other actors in the network.To facilitate the flow of knowledge on climate change adaptation,CFS activities should be conducted regularly and CFS models that fit the situation of farmers’vulnerability to climate change should be developed.
基金Projects(2013CB632601,2013CB632604)supported by the National Basic Research Program of ChinaProject(51125018)supported by the National Science Foundation for Distinguished Young Scholars of China+1 种基金Project(KGZD-EW-201-2)supported by the Key Research Program of the Chinese Academy of SciencesProjects(51374191,21106167,51104139)supported by the National Natural Science Foundation of China
文摘The reduction behaviors of FeO·V2O3 and FeO·Cr2O3 during coal-based direct reduction have a decisive impact on the efficient utilization of high-chromium vanadium-bearing titanomagnetite concentrates. The effects of molar ratio of C to Fe n(C)/n(Fe) and temperature on the behaviors of vanadium and chromium during direct reduction and magnetic separation were investigated. The reduced samples were characterized by X-ray diffraction(XRD), scanning election microscopy(SEM) and energy dispersive spectrometry(EDS) techniques. Experimental results indicate that the recoveries of vanadium and chromium rapidly increase from 10.0% and 9.6% to 45.3% and 74.3%, respectively, as the n(C)/n(Fe) increases from 0.8 to 1.4. At n(C)/n(Fe) of 0.8, the recoveries of vanadium and chromium are always lower than 10.0% in the whole temperature range of 1100-1250 °C. However, at n(C)/n(Fe) of 1.2, the recoveries of vanadium and chromium considerably increase from 17.8% and 33.8% to 42.4% and 76.0%, respectively, as the temperature increases from 1100 °C to 1250 °C. At n(C)/n(Fe) lower than 0.8, most of the FeO·V2O3 and FeO·Cr2O3 are not reduced to carbides because of the lack of carbonaceous reductants, and the temperature has little effect on the reduction behaviors of FeO·V2O3 and FeO·Cr2O3, resulting in very low recoveries of vanadium and chromium during magnetic separation. However, at higher n(C)/n(Fe), the reduction rates of FeO·V2O3 and FeO·Cr2O3 increase significatly because of the excess amount of carbonaceous reductants. Moreover, higher temperatures largely induce the reduction of FeO·V2O3 and FeO·Cr2O3 to carbides. The newly formed carbides are then dissolved in the γ(FCC) phase, and recovered accompanied with the metallic iron during magnetic separation.
基金Project(51134002)supported by the National Natural Science Foundation of ChinaProject(2012BAB14B02)supported by the Ministry of Science and Technology of ChinaProject(12120113086600)supported by Ministry of Land and Resources of China
文摘A low-grade nickel laterite ore was reduced at different reduction temperatures. The morphology of metallic particles was investigated by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). Experimental results indicate that the metallic nickel and iron gradually assemble and grow into larger spherical particles with increasing temperature and prolonging time. After reduction, the nickel laterite ore obviously changes into two parts of Fe-Ni metallic particles and slag matrix. An obvious relationship is found between the reduction of iron magnesium olivine and its crystal chemical properties. The nickel and iron oxides are reduced to metallic by reductant, and the lattice of olivine is destroyed. The entire reduction process is comprised of oxide reduction and metallic phase growth.
基金This work was financially supported by the National Key R&D Program of China(Nos.2020YFC1806504 and 2019YFC1904903)the Yue Qi Young Scholar Project,China University of Mining&Technology(Beijing)(No.2017QN12).
文摘Zeolite derived from coal-based solid wastes(coal gangue and coal fly ash)can overcome the environmental problems caused by coal-based solid wastes and achieve valuable utilization.In this paper,the physicochemical properties of coal gangue and coal fly ash are introduced.The mechanism and application characteristics of the pretreatment processes for zeolite synthesis from coal-based solid wastes are also introduced.The synthesis processes of coal-based solid waste zeolite and their advantages and disadvantages are summarized.Furthermore,the application characteristics of various coal-based solid waste zeolites and their common application fields are illustrated.Finally,we propose an alkaline fusion-assisted supercritical hydrothermal crystallization as an efficient method for synthesizing coal-based solid waste zeolites.In addition,more attention should be given to the recycling of alkaline waste liquid and the application of coal-based solid waste zeolites in the field of volatile organic compound adsorption removal.
基金financially supported by the National Natural Science Foundation of China (No.51604063)
文摘To understand the migration mechanisms of phosphorus(P)during coal-based reduction,a high-phosphorus oolitic iron ore was reduced by coal under various experimental conditions.The migration characteristics and kinetics of P were investigated by a field-emission electron probe microanalyzer(FE-EPMA)and using the basic principle of solid phase mass transfer,respectively.Experimental results showed that the P transferred from the slag to the metallic phase during reduction,and the migration process could be divided into three stages:phosphorus diffusing from the slag to the metallic interface,the formation of Fe P compounds at the slag metal interface and P diffusing from the slag metal interface to the metallic interior.The reduction time and temperature significantly influenced the phosphorus content of the metallic and slag phases.The P content of the metallic phase increased with increasing reduction time and temperature,while that of the slag phase gradually decreased.The P diffusion constant and activation energy were determined and a migration kinetics model of P in coal-based reduction was proposed.P diffusion in the metallic phase was the controlling step of the P migration.
文摘NaY zeolites were in-situ synthesized from coal-based kaolin via thehydrothermal method. The effects of various factors on the structure of the samples were extensivelyinvestigated. The samples were characterized by N_2 adsorption, XRD, IR and DTG-DTA methods, andthe results show that the crystallization temperature and amount of added water play an importantrole in the formation of the zeolite structure. The 4A and P zeolites are the competitive phasepresent in the resulting product. However, NaY zeolites with a higher relative crystallinity,excluding impure crystals and the well hydrothermal stability, can be synthesized from coal-basedkaolin. These zeolites possess a larger surface area and a narrow pore size distribution, and thismeans that optimization of this process might result in a commercial route to synthesize NaYzeolites from coal-based kaolin.
基金Supported by the National Science & Technology Support Project Task of China(2006BAE02B02)
文摘The intrinsic kinetic models of the Langmuir-Hinshelwood type were investigated in terms of the reaction rates of CO hydrogenation and CO_2 hydrogenation in theform of reactant fugacity. The parameters were estimated by the Universal Global Optimization using the Marquardt method. Residual error distribution and statistic tests show thatthe intrinsic kinetic models are reliable and acceptable. The mathematic model of a combined converter formed by gas-cooled and water-cooled reactor was developed and thegas-cooled reactor and the water-cooled reactor were characterized with one-dimensionalmathematic model. The distributions of temperature and concentration in the catalytic bedof the gas-cooled reactor and the water-cooled reactor in a combined converter with ayield of 1.2 Mt/a were simulated. The parallel cross linking pore model was used to describe the transfer process of multi-component diffusion system in the catalyst. The calculated value computed by the internal diffusion efficiency factor calculation model established for methanol synthesis catalyst fit the experimental value very well.
基金The authors thank the National Natural Science Foundation of China(No.51906130)the Natural Science Foundation of Shandong Province(No.ZR2019BEE053)+1 种基金the Key R&D and Development Plan of Shandong Province(2020CXGC011401)the Foundation of Shandong Key Lab of Energy Carbon Reduction and Resource Utilization,Shandong University(No.ECRRU201804)for the financial support.
文摘In this study,the Heishan coal was used to prepare a series of activated carbon(AC)samples via a vapor deposition method.The effects of the Fe(NO_(3))3/coal weight ratio on the physicochemical properties of the activated carbon were systematically investigated,and the AC samples were analyzed by the N2 adsorption-desorption technique,the scanning electron microscopy,the X-ray diffraction,the Raman spectroscopy,and the Fourier transform infrared spectroscopy.Furthermore,the adsorption properties of ethyl acetate were investigated.The results indicated that as the Fe(NO_(3))3/coal mass ratio increased from 1:8 to 1:2,the specific surface area,the total pore volume and the micropore volume initially increased and then decreased.The specific surface area increased from 560.86 m^(2)/g to 685.90 m^(2)/g,and then decreased to 299.56 m^(2)/g.The total pore volume and micropore volume increased from 0.29 cm^(3)/g and 0.17 cm^(3)/g to 0.30 cm^(3)/g and 0.22 cm^(3)/g,and then decreased to 0.16 cm^(3)/g and 0.10 cm^(3)/g,respectively.The optimized ratio was 1:8.During the activation process,iron ions infiltrated the activated carbon to promote the development of the pore structure,the pore size of which was between 2.5 nm and 3 nm in daimeter.This approach could enhance the capacity for adsorption of ethyl acetate.It is worth noting that the ACs displaying the largest specific surface area and total pore volume(685.90 m^(2)/g and 0.30 cm^(3)/g)were formed under the optimized activation conditions(950℃,20%(volume)of CO_(2),ratio 1:5),and the maximum AC capacity for adsorption of ethyl acetate was 962.62 mg/g.After seven repeated thermal regeneration experiments,the saturated AC adsorption capacity was still above 90%.
基金Project(52104257)supported by the National Natural Science Foundation of China。
文摘Beach titanomagnetite(TTM)provides a cheap alternative source of Fe and Ti,but this ore is difficult to process to make suitable concentrates for the blast furnace.Recently studies showed that it is feasible to separate Fe and Ti by coal-based direct reduction.In this study,beach TTM was selected as the research object,the effects of reducing agents on reducing atmosphere in coal-based direct reduction of beach TTM were analyzed,and the role of volatiles was also studied.The results showed that when bitumite and coke were used as reducing agents of TTM,the CO produced from volatiles was involved in the reduction reaction,and the generated CO_(2) provided the raw material for the reaction of TTM.The reduction effect of bitumite was better than that of coke.The reason is that bitumite+TTM had a higher gas generation rate and produced a higher CO partial pressure,while coke+TTM had a lower gas generation rate and produced a lower CO partial pressure.When graphite was used as a reducing agent,there was a solid-solid reaction in the early stage in the reaction.With the continuous accumulation of CO_(2),the Boudouad reaction started and accelerated.Graphite+TTM also produced a higher CO partial pressure.
基金Projects(51274240,51204209) supported by the National Natural Science Foundation of ChinaProject(2012M521545) supported by the National Postdoctoral Science Foundation of China
文摘A process of purification of coal-based coke powder as anode the treatment of coke powder with dilute hydrofluoric acid solution, for Li-ion batteries was attempted. The process started with followed by united-acid-leaching using sulfuric acid and hydrochloric acid. The effects of altering the hydrofluoric acid addition, hydrofluoric acid concentration, contact time, temperature and acid type were investigated. A minimum ash content of 0.35% was obtained when proper conditions were applied. The electrochemical performance of purified coke powder shows greatly improved electrochemical performance. The as-purified coke powder presented an initial reversible capacity of 257.4 mAh/g and a retention rate of 95% after 50 cycles. The proposed purification process paves a way to prepare a promising anode material with good performance with low cost of coke powder for Li-ion batteries.
基金support by the National Natural Science Foundation of China (No. 20776150)the National Hi-Tech Research and Development Program of China(No. 2008AA05Z308)the Special Fund for Basic Scientific Research of Central Colleges (No. 2009QH15)
文摘The role of Nil(NO3)2 in the preparation of a magnetic activated carbon is reported in this paper. Magnetic coal-based activated carbons (MCAC) were prepared from Taixi anthracite with low ash content in the presence of Ni(NO3)2. The MCAC materials were characterized by a vibrating sample magnetometer (VSM), X-ray diffraction (XRD), a scanning electric microscope (SEM), and by N2 adsorption. The cylindri- cal precursors and derived char were also subjected to thermogravimetric analysis to compare their behavior of weight losses during carbonization. The results show that MCAC has a larger surface area (1074 m21g) and a higher pore volume (0.5792 cm3/g) with enhanced mesopore ratio (by about 10~). It also has a high saturation magnetization (1.6749 emu/g) and low coercivity (43.26 Oe), which allows the material to be magnetically separated. The MCAC is easily magnetized because the nickel salt is con- vetted into Ni during carbonization and activation. Metallic Ni has a strong magnetism on account of electrostatic interaction. Added Ni(NO3)2 catalyzes the carbonization and activation process by accelerat- ing burn off of the carbon, which contributes to the development of mesopores and macropores in the activated carbon.
基金financially supported by the National Natural Science Foundation of China (No. 52022019)the National Key R&D Program of China (No. 2021YFC2901000)the Fok Ying Tung Education Foundation (No. 161045)
文摘The application of coal-based reduction in the efficient recovery of iron from refractory iron-bearing resources is comprehensively reviewed.Currently,the development and beneficiation of refractory iron-bearing resources have attracted increasing attention.However,the effect of iron recovery by traditional beneficiation methods is unacceptable.Coal-based reduction followed by magnetic separation is proposed,which adopts coal as the reductant to reduce iron oxides to metallic iron below the melting temperature.The metallic iron particles aggregate and grow,and the particle size continuously increases to be suitable for magnetic separation.The optimization and application of coal-based reduction have been abundantly researched.A detailed literature study on coal-based reduction is performed from the perspectives of thermodynamics,reduction kinetics,growth of metallic iron particles,additives,and application.The coal-based reduction industrial equipment can be developed based on the existing pyrometallurgical equipments,rotary hearth furnace and rotary kiln,which are introduced briefly.However,coal-based reduction currently mainly adopts coal as a reductant and fuel,which may result in high levels of carbon dioxide emissions,energy consumption,and pollution.Technological innovation aiming at decreasing carbon dioxide emissions is a new trend of green and sustainable development of the steel industry.Therefore,the substitution of coal with clean energy(hydrogen,biomass,etc.)for iron oxide reduction shows promise in the future.
文摘Based on the process of coal-based self-reduction and melting separation at high temperature, it was investigated that the effect of process factors on the reduction of iron and nickel oxide, the metal yield and the nickel content in ferronickel about the laterite nickel ore, was from Philippines and contented low nickel, high iron and aluminum. The results showed that if the C/O mole ratio was not higher than 0.5 and the reduction temperature was kept as 1200°C and then increased up to 1500°C, the metal could not separate from molten slag for the A series of experiments, which were only added CaF<sub>2</sub>. However, when the C/O ratio was added up to 0.6 - 0.8, the metal could separate well from the slag, and the yields of Fe and Ni increased gradually. But the nickel content in the metal declined from 1.79% to 1.34%. When the C/O ratio increased to 1.2, and the temperature of melting products obtained at 1200°C and rose to 1550°C, the separation of metal from slag could not be realized in B group of tests, which were only added hydrated lime. However, when both of CaF<sub>2</sub> and hydrated lime were added, the metal could separate from slag in C group. In order to increase the content of nickel in the metal, it is necessary to restrain the reduction of iron oxide. When the C/O mole ratio is 0.6, the nickel content of metal could be 1.79%, which was higher than the theoretical ratio 1.65% of Ni/(Ni + Fe) of the latcritic nickel ore, but the yield of nickle was only 71.3%.
基金Project(2011GH561685)supported by the China Torch Program
文摘Solid wastes derived from metallurgical industries pose a significant threat to environment. The utilization and disposal of these solid wastes are the major concern in the world. Semi-coke generated in coal-based direct reduction process of iron ore is a by-product and its suitable utilization is not available so far. In order to handle it properly, the characteristics of this by-product were comprehensively investigated. A series of analysis methods were used to demonstrate its mineral compositions, petrography and physico-chemical properties. The results reveal that the semi-coke has poor washability. The fixed carbon content of semi-coke reaches 76.11% and the gross calorific value is 28.10 MJ/kg, both of which are similar to those of traditional sinter coke breeze. Also, semi-coke ash possesses lower content of SiO2, Al2O3, S and higher content of CaO and MgO, which could improve the strength of sinter ore when partially substituting for coke breeze in sintering. Semi-coke features well-development porous structure and higher reaction activity, which predicts that the sintering speed could be elevated to some extent when employing it as a partial replacement of coke breeze, so the studies further suggest that the potential adverse effect of the high reactivity on sintering process could be weakened by adequately coarsening the semi-coke's particle size.
文摘Mathematical simulation was performed on tube-shell reactor for dimethyl ether (DME) synthesis from coal-based syngas. The model was established based on kinetics of dimethyl-ether synthesis from syngas over a bifunctional catalyst, which is mixed by methanol synthesis catalyst and dehydration catalyst as 1:1 mass ratio. Methanol synthesis from CO and CO2 and methanol dehydration were selected as three-independent reactions, CO, CO2, and DME as key components to estab- lish the one-dimensional mathematical model of the reactor. The gas concentration and temperature profiles inside the reactor tubes were obtained. The operating conditions affecting DME synthesis were also discussed based on the model. The simula- tions indicate that higher pressure and lower temperature at the inlet and rich hydrogen in the reactant are favorable in direct DME synthesis in fixed-bed process, and the temperature of boiling water affect the reactor performance seriously.
基金National Natural Science Foundation of China(42002195)National Science and Technology Major Project(2016ZX05044)National Natural Science Foundation of China(42130802)。
文摘Efficient detection of coalbed methane(CBM) co-production interference is the key to timely adjusting the development plan and improving the co-production efficiency. Based on production data of six typical CBM co-production wells in the Zhijin block of western Guizhou Province, China, the production characteristic curves, including production indication curve, curve of daily water production per unit drawdown of producing fluid level with time, and curve of water production per unit differential pressure with time have been analyzed to explore the response characteristics of co-production interference on the production characteristic curves. Based on the unit water inflow data of pumping test in coal measures, the critical value of in-situ water production of the CBM wells is 2 m^(3)/(d·m). The form and the slope of the initial linear section of the production indication curves have clear responses to the interference, which can be used to discriminate internal water source from external water source based on the critical slope value of 200 m^(3)/MPa in the initial linear section of the production indication curve. The time variation curves of water production per unit differential pressure can be divided into two morphological types: up-concave curve and down-concave curve. The former is represented by producing internal water with average daily gas production greater than 800 m^(3)/d, and the latter produces external water with average daily gas production smaller than 400 m^(3)/d. The method and critical indexes for recognition of CBM co-production interference based on the production characteristic curve are constructed. A template for discriminating interference of CBM co-production was constructed combined with the gas production efficiency analysis, which can provide reference for optimizing co-production engineering design and exploring economic and efficient co-production mode.
文摘The application of big data technology provides support for the co-production of public safety services.Existing research often focuses on how technology influences co-production,but lacks attention to the key actors that drive co-production and the mechanisms that facilitate it.This study examines the role of government in the digital co-production of public safety services,using the practice of Shenzhen as a case study.Shenzhen has built 125 information systems based on over 100 billion pieces of big data,forming a model of digital safety service co-production.The study reveals three types of digital co-production,characterized by"government-business joint planning,passive participation of businesses and the public,and active cooperation among government,businesses,and the public"in the"design-production-application"stages.The study shows that the government is not only a co-producer but also a proactive actor in activating the willingness of non-governmental entities to participate.Local governments mobilize non-governmental participation through three mechanisms:empowerment,profit enhancement,and value co-creation.The"power-interest-value"paradigm is applicable for analyzing the co-production of public services and helps to explain the transformation mechanisms of co-production behavior.
基金support by Shaanxi Province Technological Innovation Guidance Special (Grant No.2021QFY04-01)technical support by Analytical Instrumentation Center of XUST.
文摘The scalable production of high grade activated carbon from abundant coal for supercapacitors application is an efficient way to achieve high value-added utilization of coal sources.However,this technology is challenging due to lack of comprehensive understanding on the mechanism of activation process and effect of external factors.In this paper,the effect of activating temperature and time on the specific capacitance of coal-based activated carbon prepared by H2O steam activation was studied using the response surface method.Under optimal conditions,coal-based activated carbon exhibits the largest specific capacitance of 194.35 F·g^(−1),thanks to the appropriate pore/surface structure and defect degree.Density functional theory calculations explain in detail the mechanism of contraction of aromatic rings and overflow of H2 and CO during the activation.Meanwhile,oxygen-containing functional groups are introduced,contributing to the pseudocapacitance property of coal-based activated carbon.This mechanism of reactions between aromatic carbon and H2O vapor provides understanding on the role of water during coal processing at the molecular level,offering great potential to regulate product distribution and predict rate of pore generation.This insight would contribute to the advancement of other coal processing technology such as gasification.
基金Project supported by the Ningxia Natural Science Foundation of China(2023AAC03285)National Natural Science Foundation of China(21666001)+1 种基金Innovative Team for Transforming Waste Cooking Oil into Clean Energy and High Value-added Chemicals,ChinaNingxia Low-grade Resource High Value Utilization and Environmental Chemical Integration Technology Innovation Team Project,China。
文摘A novel composite photocatalyst for photocatalytic decomposition of water for hydrogen evolution was successfully synthesized by in-situ growth of nitrogen and sulfur co-doped coal-based carbon quantum dots(NSCQDs)nanoparticles on the surface of sheet cobalt-based metal-organic framework(Co-MOF)and graphitic carbon nitride(g-C_(3)N_(4),CN).The structure and properties of the obtained catalysts were systematically analyzed.NSCQDs effectively broaden the absorption of Co-MOF and CN in the visible region.The new composite photocatalyst has high hydrogen production activity and the hydrogen production rate reaches 6254μmol/(g·h)at pH=9.At the same time,NSCQDs synergy Co-MOF/CN composites have good stability.After four cycles of hydrogen production,the performance remains relatively stable.The tran sient photocurrent response and Nyquist plot experimental results further demonstrate the improvement of carrier separation efficiency in composite catalysts.The semiconductor type(n-type semico nductor)of the single-phase catalyst was determined by the Mott-Schottky test,and the band structure was analyzed.The conductive and valence bands of CN are-0.99 and 1.72 eV,respectively,and the conduction and valence bands of Co-MOF are-1.85 and 1.33 eV,respectively.Th e mechanism of the photocatalytic reaction can be inferred,that is,Z-type heterojunction is formed between CN an d Co-MOF,and NSCQDs was used as cocatalyst.
基金supported by the National Natural Science Foundation of China(No.22008018)China Postdoctoral Science Foundation(No.2020M670716)+5 种基金the Natural Science Foundation of Liaoning Province,China(No.2020-MS-272)the Foundation of Guangxi Key Laboratory of Clean Pulp&Papermaking and Pollution Control,College of Light Industry and Food Engineering,Guangxi University(No.2021KF08)Dalian City Outstanding Talent Project(No.2019RD13)the Start-up Fund for Doctoral Research of Dalian Polytechnic University(No.2020–07)the Foundation of State Key Laboratory of Biobased Material and Green Papermaking,Qilu University of Technology,Shandong Academy of Sciences(No.KF201914)the Foundation of Key Laboratory of State Forestry and Grassland Administration for Plant Fiber Functional Materials(No.2020KFJJ06).
文摘Single-atom photocatalysts(SAPCs)have attracted great interests due to their remarkable atom utilization efficiency,excellent activity,and selectivity,yet no application in synchronous biorefinery and water splitting.Here,efficient SAPCs based on atomically dispersed Zn atoms on carbon nitride(named Zn-mCN)were produced.Experiments verified that Zn-mCN has widened adsorption range of visible-light and lowered ability of electron-hole recombination,leading to excellent photocatalytic redox activity for synchronous biorefinery and water splitting to co-produce lactic acid(selectivity up to 91.0%)and hydrogen(-15898.8μmolg^(-1)h^(-1)).This system has excellent universality for small-molecule monosaccharides and macromolecular xylan.Poisoning experiments showed that h^(+),1O2,·O_(2)-and·OH can promote the simultaneous production of lactic acid and hydrogen.This work realized full utilization of whole redox reaction and provided a novel strategy for efficient and concomitant production of hydrogen and value-added chemicals from biomass-derived feedstocks aqueous solutions.