The novel Fe-N co-doped ordered mesoporous carbon with high catalytic activity in m-cresol removal was prepared by urea-assisted impregnation and simple pyrolysis method.During the preparation of the Fe-NC catalyst,th...The novel Fe-N co-doped ordered mesoporous carbon with high catalytic activity in m-cresol removal was prepared by urea-assisted impregnation and simple pyrolysis method.During the preparation of the Fe-NC catalyst,the complexation of N elements in urea could anchor Fe,and the formation of C3N4during urea pyrolysis could also prevent migration and aggregation of Fe species,which jointly improve the dispersion and stability of Fe.The FeN4sites and highly dispersed Fe nanoparticles synergistically trigger the dual-site peroxymonosulfate (PMS) activation for highly efficient m-cresol degradation,while the ordered mesoporous structure of the catalyst could improve the mass transfer rate of the catalytic process,which together promote catalytic degradation of m-cresol by PMS activation.Reactive oxygen species (ROS) analytic experiments demonstrate that the system degrades m-cresol by free radical pathway mainly based on SO_(4)^(-)·and·OH,and partially based on·OH as the active components,and a possible PMS activation mechanism by 5Fe-50 for m-cresol degradation was proposed.This study can provide theoretical guidance for the preparation of efficient and stable catalysts for the degradation of organic pollutants by activated PMS.展开更多
Lithium-sulfur batteries(LSBs)have drawn significant attention owing to their high theoretical discharge capacity and energy density.However,the dissolution of long-chain polysulfides into the electrolyte during the c...Lithium-sulfur batteries(LSBs)have drawn significant attention owing to their high theoretical discharge capacity and energy density.However,the dissolution of long-chain polysulfides into the electrolyte during the charge and discharge process(“shuttle effect”)results in fast capacity fading and inferior electrochemical performance.In this study,Mn_(2)O_(3)with an ordered mesoporous structure(OM-Mn_(2)O_(3))was designed as a cathode host for LSBs via KIT-6 hard templating,to effectively inhibit the polysulfide shuttle effect.OM-Mn_(2)O_(3)offers numerous pores to confine sulfur and tightly anchor the dissolved polysulfides through the combined effects of strong polar-polar interactions,polysulfides,and sulfur chain catenation.The OM-Mn_(2)O_(3)/S composite electrode delivered a discharge capacity of 561 mAh g-1 after 250 cycles at 0.5 C owing to the excellent performance of OM-Mn_(2)O_(3).Furthermore,it retained a discharge capacity of 628mA h g-1 even at a rate of 2 C,which was significantly higher than that of a pristine sulfur electrode(206mA h g-1).These findings provide a prospective strategy for designing cathode materials for high-performance LSBs.展开更多
Attributing to the high specific capacity and low electrochemical reduction potential,lithium(Li)metal is regarded as the most promising anode for high-energy Li batteries.However,the growth of lithium dendrites and h...Attributing to the high specific capacity and low electrochemical reduction potential,lithium(Li)metal is regarded as the most promising anode for high-energy Li batteries.However,the growth of lithium dendrites and huge volume change seriously limit the development of lithium metal batteries.To overcome these challenges,an ordered mesoporous N-doped carbon with lithiophilic single atoms is proposed to induce uniform nucleation and deposition of Li metal.Benefiting from the synergistic effects of interconnected three-dimensional ordered mesoporous structures and abundant lithiophilic single-atom sites,regulated local current density and rapid mass transfer can be achieved,leading to the uniform Li deposition with inhibition of dendrites and buffered volume expansion.As a result,the as-fabricated anode exhibits a high CE of 99.8%for 200 cycles.A stable voltage hysteresis of 14 mV at 5 mA cm^(−2)could be maintained for more than 1330 h in the symmetric cell.Furthermore,the full cell coupled with commercial LiFePO_(4)exhibits high reversible capacity of 108 mAh g^(−1)and average Coulombic efficiency of 99.8%from 5th to 350th cycles at 1 C.The ordered mesoporous carbon host with abundant lithiophilic single-atom sites delivers new inspirations into rational design of high-performance Li metal anodes.展开更多
Highly ordered mesoporous NiMoO4 material was successfully synthesized using mesoporous silica KIT-6 as hard template via vacuum nanocasting method. The structure was characterized by means of XRD, TEM, N2 adsorption-...Highly ordered mesoporous NiMoO4 material was successfully synthesized using mesoporous silica KIT-6 as hard template via vacuum nanocasting method. The structure was characterized by means of XRD, TEM, N2 adsorption-desorption, Raman and FT-IR. The mesoporous NiMoO4 with the coexistence of a-NiMoO4 and fl-NiMoO4 showed well-ordered mesoporous structure, a bimodal pore size distribution and crystalline framework. The catalytic performance of NiMoOa was investigated for oxidative dehydrogenation of propane. It is demonstrated that the mesoporous NiMoO4 catalyst with more surface active oxygen species showed better catalytic performance in oxidative dehydrogena- tion of propane in comparison with bulk NiMoO4.展开更多
Titanium-doped ordered mesoporous alumina with specific structural properties has been prepared by the evaporation induced self-assembly sol-gel method. The results show that the doped titanium helps to stabilize the ...Titanium-doped ordered mesoporous alumina with specific structural properties has been prepared by the evaporation induced self-assembly sol-gel method. The results show that the doped titanium helps to stabilize the ordered mesoporous alumina material without influencing the ordered mesoporosity. The textural properties of the obtained sample are related to the amount of doped titanium. When the molar ratio of aluminum to titanium (n(Al)/n(Ti)) is controlled as 10.2, the titanium-doped ordered mesoporous alumina exhibits high surface area (up to 218 m^2 g^-1), large pore volume (0.42 cm^3 g^-1) and narrow pore diameter (6.1 nm) after treating at 900 ℃, showing high thermal stability. Moreover, the obtained sample calcined at 900 ℃ still maintains ordered mesoporous structure and exhibits high thermal stability.展开更多
Metal-free, heteroatom functionalized carbon-based catalysts have made remarkable progress in recent years in a wide range of applications related to energy storage and energy generation. In this study, high surface a...Metal-free, heteroatom functionalized carbon-based catalysts have made remarkable progress in recent years in a wide range of applications related to energy storage and energy generation. In this study, high surface area mesoporous ordered sulphur doped carbon materials are obtained via one-pot hydrothermal synthesis of carbon/SBA-15 composite after removal of in-situ synthesized hard template SiO2. 2-thiophenecarboxy acid as sulphur source gives rise to sulphur doping level of 5.5 wt%. Comparing with pristine carbon, the sulphur doped mesoporous ordered carbon demonstrates improved electro-catalytic activity in the oxygen reduction reaction in alkaline solution. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.展开更多
Ordered mesoporous silica were synthesized under different conditions:hydrothermal synthesis in basic medium,room temperature synthesis in acid medium and sol gel synthesis in neutral medium,and pore structure,specif...Ordered mesoporous silica were synthesized under different conditions:hydrothermal synthesis in basic medium,room temperature synthesis in acid medium and sol gel synthesis in neutral medium,and pore structure,specific surface area and pore size distribution of samples were studied and compared in detail by means of SAXRD,HRTEM,BET,FT IR.The results show that the mesopores in the samples obtained via above three methods all possess uniform hexagonal arrays in short range.Mesoporous silica obtained in acid medium possesses narrow pore size distribution centered around 1.24nm with specific surface area of 1220 m 2·g -1 ;Mesoporous silica obtained in basic medium by hydrothermal synthesis at 160℃ possesses narrow pore size distribution centered around 1.90nm with specific surface area of 542.8 m 2·g -1 ;and mesoporous silica obtained in neutral medium by sol gel synthesis possesses broader pore size distribution centered around 4.01nm,specific surface area of 485.0 m 2·g -1 .Therefore,ordered mesoporous silicas with different pore sizes can be prepared using various synthetic methods and conditions.After heat treatment,Si O Si bending vibration strengthens and the adsorption peak of asymmetrical Si O Si stretching vibration broadens,and the crosslinking and condensation reaction of silica skeleton strengthen, meanwhile the amount of active centers of hydroxyl group on the surface of mesopores may be influenced,thus chemical assembly activity of mesopores may also be influenced.展开更多
In this paper,ordered mesoporous alumina(OMA)support with the high surface area(328 m^(2)g^(-1))and the large pore volume 0.74(cm^(3)·g^(-1))was synthesized by homogeneous precipitation method.And the influence o...In this paper,ordered mesoporous alumina(OMA)support with the high surface area(328 m^(2)g^(-1))and the large pore volume 0.74(cm^(3)·g^(-1))was synthesized by homogeneous precipitation method.And the influence of EDTA on the physical and chemical properties of the modified catalysts was also studied.The characteristic results showed that the addition of EDTA could adjust the metal-support interaction and improved the acidity of the corresponding catalyst.Combined with the catalytic performance results,the EDTA-modified Ni Mo E(1.0)/OMA catalyst displays the highest DBT hydrodesulfurization conversion(97.7%).展开更多
Chemically modified ordered mesoporous carbon CMK-3 materials were prepared by means of an easy wet-oxidative method in 2 mol/L nitric acid aqueous solution. A large amount of oxygen-containing functional groups were ...Chemically modified ordered mesoporous carbon CMK-3 materials were prepared by means of an easy wet-oxidative method in 2 mol/L nitric acid aqueous solution. A large amount of oxygen-containing functional groups were introduced onto the CMK-3 surface. Modified CMK-3(m-CMK-3) and aniline monomer were polymerized via an in situ chemical oxidative polymerization method. Morphological characterizations of m-CMK-3/PANI (polyaniline) composites were carried out via field emission scanning electron microscopy(SEM). Their electrochemical properties were investigated with cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy. The m-CMK-3/PANI composites have excellent properties in capacitance, and the highest specific capacitance(SC) value was up to 489 F/g, suggesting their potential application in the electrode material for electrochemical capacitors.展开更多
By utilizing hard template method to adjust the mesopore length, and alkali activation to generate micro pores, two hierarchical porous carbons (HPCs) were prepared. With controlling of their mesopore length and the a...By utilizing hard template method to adjust the mesopore length, and alkali activation to generate micro pores, two hierarchical porous carbons (HPCs) were prepared. With controlling of their mesopore length and the activation conditions, the complex system composed by HPCs and electrolyte was simplified and the effect of mesopore length on the performance of HPCs as electrodes in supercapacitors was investigated. It is found that with the mesopore length getting smaller, the ordered area gets smaller and the aggregation occurs, which is caused by the high surface energy of small grains. HPC with long pores (HPCL) exhibits a donut-like morphology with well-defined ordered mesopores and a regular orientation while in HPC with short pores (HPCS), short mesopores are only orderly distributed in small regions. Longer ordered channels form unobstructed ways for ions transport in the particles while shorter channels, only orderly distributed in small areas, results in blocked paths, which may hinder the electrolyte ions transport. Due to the unobstructed structure, HPCL exhibits good rate capability with a capacitance retention rate over 86% as current density increasing from 50 mA/g to 1000 mA/g. The specific capacitance of HPCL derived from the cyclic voltammetry test at 10 mV/s is up to 201.72 F/g, while the specific capacitance of HPCS is only 193.65 F/g. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.展开更多
In this work, nitrogen-doped cobalt nanoparticlesinitrogen-doped plate-like ordered mesoporous carbons (N/Co/OMCs) were used as noble-metal free electrocatalysts with high catalytic efficiency. Compared with OMCs with...In this work, nitrogen-doped cobalt nanoparticlesinitrogen-doped plate-like ordered mesoporous carbons (N/Co/OMCs) were used as noble-metal free electrocatalysts with high catalytic efficiency. Compared with OMCs with long channel length, due to more entrances for catalytic target accessibility and a short pathway for rapid diffusion, the utilization efficiency of cobalt nanoparticles inside the plate-like OMCs with short pore length is well improved, which can take full advantage of porous structure in electrocatalysis and increase the utilization of catalysts. The active sites in N/Co/OMCs for oxygen reduction reaction (ORR) are highly exposed to oxygen molecule, which results in a high activity for ORR. By combination of the catalytic properties of nitrogen dopant, incorporation of Co nanoparticles, and structural properties of OMCs, the N/Co/plate-like OMCs are highly active noble-metal free catalysts for ORR in alkaline solution. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.展开更多
A binder-free Ir-dispersed ordered mesoporous carbon(Ir-OMC) catalytic electrode has been prepared through a designed in-situ carbonization method, which involves coating resorcinol and formaldehyde mixtures with ir...A binder-free Ir-dispersed ordered mesoporous carbon(Ir-OMC) catalytic electrode has been prepared through a designed in-situ carbonization method, which involves coating resorcinol and formaldehyde mixtures with iridium precursors onto the three-dimensional nickel foam framework, followed by insitu calcination in Natmosphere at 800 ℃ for 3 h. This electrode shows a large surface area, ordered mesoporous structure and homogeneous distribution of metal nanoparticles. It presents good activity and stability towards hydrogen evolution reaction, which is attributed to the efficient mass and electron transport from the intimate contact among Ir nanoparticles, ordered mesoporous carbon matrix and 3 D conductive substrate. We hope that this in-situ carbonization synthetic route can also be applied to design more high-performance catalysts for water splitting, fuel cells and other clean energy devices.展开更多
A series of 3 wt% Ru embedded on ordered mesoporous carbon (OMC) catalysts with different pore sizes were prepared by autoreduction between ruthenium precursors and carbon sources at 1123 K. Ru nanoparticles were em...A series of 3 wt% Ru embedded on ordered mesoporous carbon (OMC) catalysts with different pore sizes were prepared by autoreduction between ruthenium precursors and carbon sources at 1123 K. Ru nanoparticles were embedded on the carbon walls of OMC. Characterization technologies including power X-ray diffraction (XRD), nitrogen adsorption-desorption, transmission electron microscopy (TEM), and hydrogen temperature-programmed reduction (H2-TPR) were used to scrutinize the catalysts. The catalyst activity for Fischer-Tropsch synthesis (FTS) was measured in a fixed bed reactor. It was revealed that 3 wt% Ru-OMC catalysts exhibited highly ordered mesoporous structure and large surface area. Compared with the catalysts with smaller pores, the catalysts with larger pores were inclined to form larger Ru particles. These 3 wt% Ru-OMC catalysts with different pore sizes were more stable than 3 wt% Ru/AC catalyst during the FTS reactions because Ru particles were embedded on the carbon walls, suppressing particles aggregation, movement and oxidation. The catalytic activity and C5+ selectivity were found to increase with the increasing pore size, however, CH4 selectivity showed the opposite trend. These changes may be explained in terms of the special environment of the active Ru sites and the diffusion of products in the pores of the catalysts, suggesting that the activity and hydrocarbon selectivity are more dependent on the pore size of OMC than on the Ru particle size.展开更多
Simple encapsulation of 3 nm gold nanoparticles in ordered mesoporous carbon with large pores of 17 nm and thick pore walls of 16 nm was achieved by a metal–ligand coordination assisted-selfassembly approach.Polystyr...Simple encapsulation of 3 nm gold nanoparticles in ordered mesoporous carbon with large pores of 17 nm and thick pore walls of 16 nm was achieved by a metal–ligand coordination assisted-selfassembly approach.Polystyrene-block-polyethylene-oxide(PS-b-PEO)diblock copolymer with a large molecular weight of the PS chain and mercaptopropyltrimethoxysilane were used as the template and the metal ligand,respectively.Small-angle X-ray scattering,X-ray diffraction,transmission electron microscopy,and X-ray photoelectron spectroscopy showed that monodispersed aggregation-free gold nanoparticles approximately 3 nm in size were partially embedded in the large open pore structure of the ordered mesoporous carbon.The strong coordination between the gold species and the mercapto groups and the thick porous walls increased the dispersion of the gold nanoparticles and essentially inhibited particle aggregation at 600℃.The gold nanoparticles in the ordered mesoporous carbon are active and stable in the reduction of nitroarenes involving bulky molecules using sodium borohydride as a reducing agent under ambient conditions(30℃)in water.The large interconnected pore structure facilitates the mass transfer of bulky molecules.展开更多
Efficiently reducing carbon dioxide(CO_(2))into carbon chemicals and fuels is highly desirable due to the rapid growth of atmospheric CO_(2)ncentration.In prior work,we described a unique H/CO_(2)fuel cell driven by l...Efficiently reducing carbon dioxide(CO_(2))into carbon chemicals and fuels is highly desirable due to the rapid growth of atmospheric CO_(2)ncentration.In prior work,we described a unique H/CO_(2)fuel cell driven by low-valued waste heat,which not only CO_(2)nverts CO_(2)to methane(CH_(4))but also outputs electrical energy,yet the CO_(2)reduction rate needs to be urgently improved.Here,a novel Ru-RuOcatalyst with heterostructure was grafted on mesoporous carbon spheres by in situ partially reducing RuOinto ultrasmall Ru clusters(~1 nm),in which heteroatom-doped carbon spheres as a matrix with excellent CO_(2)nductivity and abundant pores can not only easily CO_(2)nfine the formation of Ru nanocluster but also are beneficial to the exposed active sites of Ru CO_(2)mplex and the mass transport.CO_(2)mpared to pure RuOnanoparticles supported on carbon spheres,our CO_(2)mposite catalyst boosts the CO_(2) nversion rate by more than 5-fold,reaching a value of 382.7μmol gcat.h-1at 170℃.Moreover,a decent output power density of 2.92 W mwas obtained from this H2/CO_(2)fuel cell using Ru-RuOembedded carbon spheres as a cathode catalyst.The Ru-RuOheterostructure can modify the adsorption energy of CO_(2)and induce the redistribution of charge density,thus boosting CO_(2)reduction significantly.This work not only offers an efficient catalyst for this novel H_(2)/CO_(2)fuel cell but also presents a facile method to prepare Ru nanoclusters.展开更多
Ordered mesoporous carbon (OMC) and metal-doped (M-doped) OMC composites are prepared, and their electromagnetic (EM) parameters are measured. Using the measured EM parameters we calculate the EM wave absorption...Ordered mesoporous carbon (OMC) and metal-doped (M-doped) OMC composites are prepared, and their electromagnetic (EM) parameters are measured. Using the measured EM parameters we calculate the EM wave absorption properties of a double-layer absorber, which is composed of OMC as an absorbing layer and M-doped OMC as the matching layer. The calculated results show that the EM wave absorption performance of OMC/OMC–Co (2.2mm/2.1mm) is improved remarkably. The obtained effective absorption bandwidth is up to 10.3 GHz and the minimum reflection loss reaches 47.6 dB at 14.3 GHz. The enhanced absorption property of OMC/OMC–Co can be attributed to the impedance match between the air and the absorber. Moreover, it can be found that for the absorber with a given matching layer, a larger value of -tanδ ε (= tan δ ε absorbing tan δε matching ) can induce better absorption performance, indicating that the difference in impedance between the absorbing layer and the matching layer plays an important role in improving the absorption property of double-layer absorbers.展开更多
Rechargeable lithium-sulfur(Li-S)batteries are promising candidates for next-generation batteries because of their high theoretical specific capacity(1675 mAh/g)and specific energy(2600 Wh/kg);more-over,S is abundant,...Rechargeable lithium-sulfur(Li-S)batteries are promising candidates for next-generation batteries because of their high theoretical specific capacity(1675 mAh/g)and specific energy(2600 Wh/kg);more-over,S is abundant,inexpensive,non-toxic,and environment friendly.However,the inherent insulating nature of S,discharge products of Li 2S,and dissolution of Li polysulfides(LiPSs)severely limit the practical applications of Li-S batteries.In this study,an N-doped ordered mesoporous carbon(NOMC)with a large specific surface area and high pyridinic N content was successfully prepared via the hard templating method.The synergetic effects of physical nanoconfinement and chemisorption restricted the LiPSs dissolution in the electrolyte.Graphitic N improved the electrical conductivity of the C materials,and pyridinic N effectively adsorbed the LiPSs,thereby inhibiting the shuttling of polysulfides in the electrolyte.The obtained C material was used as an S host,and the resultant S@NOMC composite exhibited a first discharge capacity of 853 mAh/g.The capacity of the composite was retained at 679 mAh/g after 500 cycles at 1 C,which corresponds to a decay rate of 0.042%per cycle.展开更多
To improve the initial coulombic efficiency and bulk density of ordered mesoporous carbons, active Fe203 nanoparticles were introduced into tubular mesopore channels of CMK-5 carbon, which possesses high specific surf...To improve the initial coulombic efficiency and bulk density of ordered mesoporous carbons, active Fe203 nanoparticles were introduced into tubular mesopore channels of CMK-5 carbon, which possesses high specific surface area (〉1700 m2.g-1) and large pore volume (〉1.8 cm3-g-1). Fine Fe203 nanoparticles with sizes in the range of 5-7 nm were highly and homogenously encapsulated into CMK-5 matrix through ammonia-treatment and subsequent pyrolysis method. The Fe203 loading was carefully tailored and designed to warrant a high Fe203 content and adequate buffer space for improving the electrochemical performance. In particular, such Fe203 and mesoporous carbon composite with 47 wt% loading exhibits a considerably stable cycle performance (683 mAh.g-1 after 100 cycles, 99% capacity retention against that of the second cycle) as well as good rate capability. The fabrication strategy can effectively solve the drawback of single material, and achieve a high-performance lithium electrode material.展开更多
In spite of silicon has a superior theoretical capacity, the large volume expansion of Si anodes during Li^+ insertion/extraction is the bottle neck that results in fast capacity fading and poor cycling performance. I...In spite of silicon has a superior theoretical capacity, the large volume expansion of Si anodes during Li^+ insertion/extraction is the bottle neck that results in fast capacity fading and poor cycling performance. In this paper, we report a silicon, single-walled carbon nanotube, and ordered mesoporous carbon nanocomposite synthesized by an evaporation-induced self-assembly process, in which silicon nanoparticles and single-walled carbon nanotubes were added into the phenolic resol with F-127 for co-condensation. The ordered mesoporous carbon matrix and single-walled carbon nanotubes network could effectively accommodate the volume change of silicon nanoparticles, and the ordered mesoporous structure could also provide efficient channels for the fast transport of Li-ions. As a consequence, this hybrid material exhibits a reversible capacity of 861 mAh g^(-1) after 150 cycles at a current density of 400 mAg^(-1). It achieves significant improvement in the electrochemical performance when compared with the raw materials and Si nanoparticle anodes.展开更多
VO2/ordered mesoporous carbon (CMK-3) composites were prepared by solid-state reaction process. The microstructures were characterized by X-ray diffraction (XRD), nitrogen adsorption and desorption, field-emission...VO2/ordered mesoporous carbon (CMK-3) composites were prepared by solid-state reaction process. The microstructures were characterized by X-ray diffraction (XRD), nitrogen adsorption and desorption, field-emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The experimental results showed that the vanadium oxide in the composites was vanadium dioxide (VO2) with monoclinic structure, which was artificially loaded on the outer surface of CMK-3. VO2/ordered mesoporous carbon composites present a significantly improved capacitive performance (131 F/g) increased by 40.86% compared to that of CMK-3 carbon (93 F/g). Therefore, as-prepared VO2/mesoporous carbon composites suggest promising applications in hybrid capacitors.展开更多
基金gratefully acknowledge the financial support of the National Natural Science Foundation of China(22108145 and 21978143)the Shandong Province Natural Science Foundation(ZR2020QB189)+1 种基金State Key Laboratory of Heavy Oil Processing(SKLHOP202203008)the Talent Foundation funded by Province and Ministry Co-construction Collaborative Innovation Center of Eco-chemical Engineering(STHGYX2201).
文摘The novel Fe-N co-doped ordered mesoporous carbon with high catalytic activity in m-cresol removal was prepared by urea-assisted impregnation and simple pyrolysis method.During the preparation of the Fe-NC catalyst,the complexation of N elements in urea could anchor Fe,and the formation of C3N4during urea pyrolysis could also prevent migration and aggregation of Fe species,which jointly improve the dispersion and stability of Fe.The FeN4sites and highly dispersed Fe nanoparticles synergistically trigger the dual-site peroxymonosulfate (PMS) activation for highly efficient m-cresol degradation,while the ordered mesoporous structure of the catalyst could improve the mass transfer rate of the catalytic process,which together promote catalytic degradation of m-cresol by PMS activation.Reactive oxygen species (ROS) analytic experiments demonstrate that the system degrades m-cresol by free radical pathway mainly based on SO_(4)^(-)·and·OH,and partially based on·OH as the active components,and a possible PMS activation mechanism by 5Fe-50 for m-cresol degradation was proposed.This study can provide theoretical guidance for the preparation of efficient and stable catalysts for the degradation of organic pollutants by activated PMS.
基金Ministry of Trade,Industry and Energy,Grant/Award Number:20010095Korea Evaluation Institute of Industrial Technology,Grant/Award Number:20012341。
文摘Lithium-sulfur batteries(LSBs)have drawn significant attention owing to their high theoretical discharge capacity and energy density.However,the dissolution of long-chain polysulfides into the electrolyte during the charge and discharge process(“shuttle effect”)results in fast capacity fading and inferior electrochemical performance.In this study,Mn_(2)O_(3)with an ordered mesoporous structure(OM-Mn_(2)O_(3))was designed as a cathode host for LSBs via KIT-6 hard templating,to effectively inhibit the polysulfide shuttle effect.OM-Mn_(2)O_(3)offers numerous pores to confine sulfur and tightly anchor the dissolved polysulfides through the combined effects of strong polar-polar interactions,polysulfides,and sulfur chain catenation.The OM-Mn_(2)O_(3)/S composite electrode delivered a discharge capacity of 561 mAh g-1 after 250 cycles at 0.5 C owing to the excellent performance of OM-Mn_(2)O_(3).Furthermore,it retained a discharge capacity of 628mA h g-1 even at a rate of 2 C,which was significantly higher than that of a pristine sulfur electrode(206mA h g-1).These findings provide a prospective strategy for designing cathode materials for high-performance LSBs.
基金supported by the National Key Research and Development Program of China(2020YFA0715000)the National Natural Science Foundation of China(51832004,52127816)+2 种基金the Programme of Introducing Talents of Discipline to Universities(B17034)China,Foshan Xianhu Laboratory of the Advanced Energy Science,China and Technology Guangdong Laboratory(XHT2020-003)the project supported by State Key Laboratory of Advanced Technology for Materials Synthesis and Processing(WUT:2022-KF-5).
文摘Attributing to the high specific capacity and low electrochemical reduction potential,lithium(Li)metal is regarded as the most promising anode for high-energy Li batteries.However,the growth of lithium dendrites and huge volume change seriously limit the development of lithium metal batteries.To overcome these challenges,an ordered mesoporous N-doped carbon with lithiophilic single atoms is proposed to induce uniform nucleation and deposition of Li metal.Benefiting from the synergistic effects of interconnected three-dimensional ordered mesoporous structures and abundant lithiophilic single-atom sites,regulated local current density and rapid mass transfer can be achieved,leading to the uniform Li deposition with inhibition of dendrites and buffered volume expansion.As a result,the as-fabricated anode exhibits a high CE of 99.8%for 200 cycles.A stable voltage hysteresis of 14 mV at 5 mA cm^(−2)could be maintained for more than 1330 h in the symmetric cell.Furthermore,the full cell coupled with commercial LiFePO_(4)exhibits high reversible capacity of 108 mAh g^(−1)and average Coulombic efficiency of 99.8%from 5th to 350th cycles at 1 C.The ordered mesoporous carbon host with abundant lithiophilic single-atom sites delivers new inspirations into rational design of high-performance Li metal anodes.
基金supported by NSFC(21073235,21173270,21177160,21376261)863 Program(2013AA065302)PetroChina Innovation Foundation(2011D-5006-0403)
文摘Highly ordered mesoporous NiMoO4 material was successfully synthesized using mesoporous silica KIT-6 as hard template via vacuum nanocasting method. The structure was characterized by means of XRD, TEM, N2 adsorption-desorption, Raman and FT-IR. The mesoporous NiMoO4 with the coexistence of a-NiMoO4 and fl-NiMoO4 showed well-ordered mesoporous structure, a bimodal pore size distribution and crystalline framework. The catalytic performance of NiMoOa was investigated for oxidative dehydrogenation of propane. It is demonstrated that the mesoporous NiMoO4 catalyst with more surface active oxygen species showed better catalytic performance in oxidative dehydrogena- tion of propane in comparison with bulk NiMoO4.
基金the financial support from the National Natural Science Foundation of China(No.51103024)Joint Research Program of Fuzhou University(No.DH-700)
文摘Titanium-doped ordered mesoporous alumina with specific structural properties has been prepared by the evaporation induced self-assembly sol-gel method. The results show that the doped titanium helps to stabilize the ordered mesoporous alumina material without influencing the ordered mesoporosity. The textural properties of the obtained sample are related to the amount of doped titanium. When the molar ratio of aluminum to titanium (n(Al)/n(Ti)) is controlled as 10.2, the titanium-doped ordered mesoporous alumina exhibits high surface area (up to 218 m^2 g^-1), large pore volume (0.42 cm^3 g^-1) and narrow pore diameter (6.1 nm) after treating at 900 ℃, showing high thermal stability. Moreover, the obtained sample calcined at 900 ℃ still maintains ordered mesoporous structure and exhibits high thermal stability.
基金supported by the University of Electronic Science and Technology of China(Y02002010301080)the National Science Foundation of China(51502032)the financial support from Natural Science Foundation of Zhejiang Province(No.LQ14E020003)
文摘Metal-free, heteroatom functionalized carbon-based catalysts have made remarkable progress in recent years in a wide range of applications related to energy storage and energy generation. In this study, high surface area mesoporous ordered sulphur doped carbon materials are obtained via one-pot hydrothermal synthesis of carbon/SBA-15 composite after removal of in-situ synthesized hard template SiO2. 2-thiophenecarboxy acid as sulphur source gives rise to sulphur doping level of 5.5 wt%. Comparing with pristine carbon, the sulphur doped mesoporous ordered carbon demonstrates improved electro-catalytic activity in the oxygen reduction reaction in alkaline solution. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.
基金theNationalNaturalScienceFoundationofChina (No .50 2 72048)andtheNaturalScienceFoundationofHubeiProvince (No .2 0 0 1ABB0 76)
文摘Ordered mesoporous silica were synthesized under different conditions:hydrothermal synthesis in basic medium,room temperature synthesis in acid medium and sol gel synthesis in neutral medium,and pore structure,specific surface area and pore size distribution of samples were studied and compared in detail by means of SAXRD,HRTEM,BET,FT IR.The results show that the mesopores in the samples obtained via above three methods all possess uniform hexagonal arrays in short range.Mesoporous silica obtained in acid medium possesses narrow pore size distribution centered around 1.24nm with specific surface area of 1220 m 2·g -1 ;Mesoporous silica obtained in basic medium by hydrothermal synthesis at 160℃ possesses narrow pore size distribution centered around 1.90nm with specific surface area of 542.8 m 2·g -1 ;and mesoporous silica obtained in neutral medium by sol gel synthesis possesses broader pore size distribution centered around 4.01nm,specific surface area of 485.0 m 2·g -1 .Therefore,ordered mesoporous silicas with different pore sizes can be prepared using various synthetic methods and conditions.After heat treatment,Si O Si bending vibration strengthens and the adsorption peak of asymmetrical Si O Si stretching vibration broadens,and the crosslinking and condensation reaction of silica skeleton strengthen, meanwhile the amount of active centers of hydroxyl group on the surface of mesopores may be influenced,thus chemical assembly activity of mesopores may also be influenced.
基金financially supported by the National Natural Science Foundation of China(No.21878330,21676298)the National Key R&D Program of China(2019YFC1907602)the CNPC Key Research Project(2016E-0707)。
文摘In this paper,ordered mesoporous alumina(OMA)support with the high surface area(328 m^(2)g^(-1))and the large pore volume 0.74(cm^(3)·g^(-1))was synthesized by homogeneous precipitation method.And the influence of EDTA on the physical and chemical properties of the modified catalysts was also studied.The characteristic results showed that the addition of EDTA could adjust the metal-support interaction and improved the acidity of the corresponding catalyst.Combined with the catalytic performance results,the EDTA-modified Ni Mo E(1.0)/OMA catalyst displays the highest DBT hydrodesulfurization conversion(97.7%).
基金Supported by the National Basic Research Program of China(No.2007CB216408)the National Natural Science Foundation of China(No.50602020)+1 种基金the Program for Outstanding Young Teachers in Lanzhou University of Technology China (No.Q200803)
文摘Chemically modified ordered mesoporous carbon CMK-3 materials were prepared by means of an easy wet-oxidative method in 2 mol/L nitric acid aqueous solution. A large amount of oxygen-containing functional groups were introduced onto the CMK-3 surface. Modified CMK-3(m-CMK-3) and aniline monomer were polymerized via an in situ chemical oxidative polymerization method. Morphological characterizations of m-CMK-3/PANI (polyaniline) composites were carried out via field emission scanning electron microscopy(SEM). Their electrochemical properties were investigated with cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy. The m-CMK-3/PANI composites have excellent properties in capacitance, and the highest specific capacitance(SC) value was up to 489 F/g, suggesting their potential application in the electrode material for electrochemical capacitors.
基金financial support from the Natural Science Foundation of China(no.51177156/E0712)
文摘By utilizing hard template method to adjust the mesopore length, and alkali activation to generate micro pores, two hierarchical porous carbons (HPCs) were prepared. With controlling of their mesopore length and the activation conditions, the complex system composed by HPCs and electrolyte was simplified and the effect of mesopore length on the performance of HPCs as electrodes in supercapacitors was investigated. It is found that with the mesopore length getting smaller, the ordered area gets smaller and the aggregation occurs, which is caused by the high surface energy of small grains. HPC with long pores (HPCL) exhibits a donut-like morphology with well-defined ordered mesopores and a regular orientation while in HPC with short pores (HPCS), short mesopores are only orderly distributed in small regions. Longer ordered channels form unobstructed ways for ions transport in the particles while shorter channels, only orderly distributed in small areas, results in blocked paths, which may hinder the electrolyte ions transport. Due to the unobstructed structure, HPCL exhibits good rate capability with a capacitance retention rate over 86% as current density increasing from 50 mA/g to 1000 mA/g. The specific capacitance of HPCL derived from the cyclic voltammetry test at 10 mV/s is up to 201.72 F/g, while the specific capacitance of HPCS is only 193.65 F/g. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.
基金financial support from the National Natural Science Foundation of China(21405011)the Science and Technology Development Planning of Jilin Province(20150520014JH)
文摘In this work, nitrogen-doped cobalt nanoparticlesinitrogen-doped plate-like ordered mesoporous carbons (N/Co/OMCs) were used as noble-metal free electrocatalysts with high catalytic efficiency. Compared with OMCs with long channel length, due to more entrances for catalytic target accessibility and a short pathway for rapid diffusion, the utilization efficiency of cobalt nanoparticles inside the plate-like OMCs with short pore length is well improved, which can take full advantage of porous structure in electrocatalysis and increase the utilization of catalysts. The active sites in N/Co/OMCs for oxygen reduction reaction (ORR) are highly exposed to oxygen molecule, which results in a high activity for ORR. By combination of the catalytic properties of nitrogen dopant, incorporation of Co nanoparticles, and structural properties of OMCs, the N/Co/plate-like OMCs are highly active noble-metal free catalysts for ORR in alkaline solution. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.
基金support of the National Natural Science Foundation of China (21403218, 21476226, 21403029)Ministry of Science and Technology of the People’s Republic of China under contact of 2016YFA0202800+2 种基金the Youth Innovation Promotion Association of the CASthe Scientific Research Project of the Education Department of Liaoning Province (L2014022)the Fundamental Research Funds for the Central Universities (DUT15ZD225)
文摘A binder-free Ir-dispersed ordered mesoporous carbon(Ir-OMC) catalytic electrode has been prepared through a designed in-situ carbonization method, which involves coating resorcinol and formaldehyde mixtures with iridium precursors onto the three-dimensional nickel foam framework, followed by insitu calcination in Natmosphere at 800 ℃ for 3 h. This electrode shows a large surface area, ordered mesoporous structure and homogeneous distribution of metal nanoparticles. It presents good activity and stability towards hydrogen evolution reaction, which is attributed to the efficient mass and electron transport from the intimate contact among Ir nanoparticles, ordered mesoporous carbon matrix and 3 D conductive substrate. We hope that this in-situ carbonization synthetic route can also be applied to design more high-performance catalysts for water splitting, fuel cells and other clean energy devices.
基金supported by the National Natural Science Foundation of China (Grant No. 21073238)the National Basic Research Program of China (Grant No. 2011CB211704)
文摘A series of 3 wt% Ru embedded on ordered mesoporous carbon (OMC) catalysts with different pore sizes were prepared by autoreduction between ruthenium precursors and carbon sources at 1123 K. Ru nanoparticles were embedded on the carbon walls of OMC. Characterization technologies including power X-ray diffraction (XRD), nitrogen adsorption-desorption, transmission electron microscopy (TEM), and hydrogen temperature-programmed reduction (H2-TPR) were used to scrutinize the catalysts. The catalyst activity for Fischer-Tropsch synthesis (FTS) was measured in a fixed bed reactor. It was revealed that 3 wt% Ru-OMC catalysts exhibited highly ordered mesoporous structure and large surface area. Compared with the catalysts with smaller pores, the catalysts with larger pores were inclined to form larger Ru particles. These 3 wt% Ru-OMC catalysts with different pore sizes were more stable than 3 wt% Ru/AC catalyst during the FTS reactions because Ru particles were embedded on the carbon walls, suppressing particles aggregation, movement and oxidation. The catalytic activity and C5+ selectivity were found to increase with the increasing pore size, however, CH4 selectivity showed the opposite trend. These changes may be explained in terms of the special environment of the active Ru sites and the diffusion of products in the pores of the catalysts, suggesting that the activity and hydrocarbon selectivity are more dependent on the pore size of OMC than on the Ru particle size.
基金supported by the National Natural Science Foun-dation of China(22025204,92034301,21773156,and 51932005)the Shanghai Sci.&Tech.and Edu.Committee(19070502700)the Innovation Program of the Shanghai Municipal Education Com-mission(2021-01-07-00-02-E00119).
文摘Simple encapsulation of 3 nm gold nanoparticles in ordered mesoporous carbon with large pores of 17 nm and thick pore walls of 16 nm was achieved by a metal–ligand coordination assisted-selfassembly approach.Polystyrene-block-polyethylene-oxide(PS-b-PEO)diblock copolymer with a large molecular weight of the PS chain and mercaptopropyltrimethoxysilane were used as the template and the metal ligand,respectively.Small-angle X-ray scattering,X-ray diffraction,transmission electron microscopy,and X-ray photoelectron spectroscopy showed that monodispersed aggregation-free gold nanoparticles approximately 3 nm in size were partially embedded in the large open pore structure of the ordered mesoporous carbon.The strong coordination between the gold species and the mercapto groups and the thick porous walls increased the dispersion of the gold nanoparticles and essentially inhibited particle aggregation at 600℃.The gold nanoparticles in the ordered mesoporous carbon are active and stable in the reduction of nitroarenes involving bulky molecules using sodium borohydride as a reducing agent under ambient conditions(30℃)in water.The large interconnected pore structure facilitates the mass transfer of bulky molecules.
基金financially supported by the Natural Science Foundation of Shaanxi Provincial(2021JQ-034)Chongqing University Key Laboratory of Micro/Nano Materials Engineering and Technology(KFJJ2012)by University Joint Project of Shaanxi Province(2021GXLH-Z-067)。
文摘Efficiently reducing carbon dioxide(CO_(2))into carbon chemicals and fuels is highly desirable due to the rapid growth of atmospheric CO_(2)ncentration.In prior work,we described a unique H/CO_(2)fuel cell driven by low-valued waste heat,which not only CO_(2)nverts CO_(2)to methane(CH_(4))but also outputs electrical energy,yet the CO_(2)reduction rate needs to be urgently improved.Here,a novel Ru-RuOcatalyst with heterostructure was grafted on mesoporous carbon spheres by in situ partially reducing RuOinto ultrasmall Ru clusters(~1 nm),in which heteroatom-doped carbon spheres as a matrix with excellent CO_(2)nductivity and abundant pores can not only easily CO_(2)nfine the formation of Ru nanocluster but also are beneficial to the exposed active sites of Ru CO_(2)mplex and the mass transport.CO_(2)mpared to pure RuOnanoparticles supported on carbon spheres,our CO_(2)mposite catalyst boosts the CO_(2) nversion rate by more than 5-fold,reaching a value of 382.7μmol gcat.h-1at 170℃.Moreover,a decent output power density of 2.92 W mwas obtained from this H2/CO_(2)fuel cell using Ru-RuOembedded carbon spheres as a cathode catalyst.The Ru-RuOheterostructure can modify the adsorption energy of CO_(2)and induce the redistribution of charge density,thus boosting CO_(2)reduction significantly.This work not only offers an efficient catalyst for this novel H_(2)/CO_(2)fuel cell but also presents a facile method to prepare Ru nanoclusters.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 50771082 and 60776822)the Doctorate Foundation (Grant No. CX201207)+2 种基金the Graduate Starting Seed Fund of Northwestern Polytechnical University (Grant No. Z2011011)the Natural Science Foundation of Shaanxi Province, China (Grant No. 2012JM1009)the Scientific Research Program Funded by Shaanxi Provincial Educational Department, China (Grant No. 12JK0984)
文摘Ordered mesoporous carbon (OMC) and metal-doped (M-doped) OMC composites are prepared, and their electromagnetic (EM) parameters are measured. Using the measured EM parameters we calculate the EM wave absorption properties of a double-layer absorber, which is composed of OMC as an absorbing layer and M-doped OMC as the matching layer. The calculated results show that the EM wave absorption performance of OMC/OMC–Co (2.2mm/2.1mm) is improved remarkably. The obtained effective absorption bandwidth is up to 10.3 GHz and the minimum reflection loss reaches 47.6 dB at 14.3 GHz. The enhanced absorption property of OMC/OMC–Co can be attributed to the impedance match between the air and the absorber. Moreover, it can be found that for the absorber with a given matching layer, a larger value of -tanδ ε (= tan δ ε absorbing tan δε matching ) can induce better absorption performance, indicating that the difference in impedance between the absorbing layer and the matching layer plays an important role in improving the absorption property of double-layer absorbers.
文摘Rechargeable lithium-sulfur(Li-S)batteries are promising candidates for next-generation batteries because of their high theoretical specific capacity(1675 mAh/g)and specific energy(2600 Wh/kg);more-over,S is abundant,inexpensive,non-toxic,and environment friendly.However,the inherent insulating nature of S,discharge products of Li 2S,and dissolution of Li polysulfides(LiPSs)severely limit the practical applications of Li-S batteries.In this study,an N-doped ordered mesoporous carbon(NOMC)with a large specific surface area and high pyridinic N content was successfully prepared via the hard templating method.The synergetic effects of physical nanoconfinement and chemisorption restricted the LiPSs dissolution in the electrolyte.Graphitic N improved the electrical conductivity of the C materials,and pyridinic N effectively adsorbed the LiPSs,thereby inhibiting the shuttling of polysulfides in the electrolyte.The obtained C material was used as an S host,and the resultant S@NOMC composite exhibited a first discharge capacity of 853 mAh/g.The capacity of the composite was retained at 679 mAh/g after 500 cycles at 1 C,which corresponds to a decay rate of 0.042%per cycle.
基金supported by the Fundamental Research Funds for the Central Universities (Grant No. DUT12ZD218)the National Natural Science Foundation of China (Grant No. 21103184)the Ph. D. Programs Foundation (Grant No. 20100041110017) of Ministry of Education of China
文摘To improve the initial coulombic efficiency and bulk density of ordered mesoporous carbons, active Fe203 nanoparticles were introduced into tubular mesopore channels of CMK-5 carbon, which possesses high specific surface area (〉1700 m2.g-1) and large pore volume (〉1.8 cm3-g-1). Fine Fe203 nanoparticles with sizes in the range of 5-7 nm were highly and homogenously encapsulated into CMK-5 matrix through ammonia-treatment and subsequent pyrolysis method. The Fe203 loading was carefully tailored and designed to warrant a high Fe203 content and adequate buffer space for improving the electrochemical performance. In particular, such Fe203 and mesoporous carbon composite with 47 wt% loading exhibits a considerably stable cycle performance (683 mAh.g-1 after 100 cycles, 99% capacity retention against that of the second cycle) as well as good rate capability. The fabrication strategy can effectively solve the drawback of single material, and achieve a high-performance lithium electrode material.
基金supported by the National Natural Science Foundation of China(NO.91434203,21276257,91534109)"Strategic Priority Research Program" of the Chinese Academy of Sciences(Grant No.XDA09010103)External Cooperation Program of BIC of the Chinese Academy of Sciences(Grant No.GJHZ201306)
文摘In spite of silicon has a superior theoretical capacity, the large volume expansion of Si anodes during Li^+ insertion/extraction is the bottle neck that results in fast capacity fading and poor cycling performance. In this paper, we report a silicon, single-walled carbon nanotube, and ordered mesoporous carbon nanocomposite synthesized by an evaporation-induced self-assembly process, in which silicon nanoparticles and single-walled carbon nanotubes were added into the phenolic resol with F-127 for co-condensation. The ordered mesoporous carbon matrix and single-walled carbon nanotubes network could effectively accommodate the volume change of silicon nanoparticles, and the ordered mesoporous structure could also provide efficient channels for the fast transport of Li-ions. As a consequence, this hybrid material exhibits a reversible capacity of 861 mAh g^(-1) after 150 cycles at a current density of 400 mAg^(-1). It achieves significant improvement in the electrochemical performance when compared with the raw materials and Si nanoparticle anodes.
基金Funded by the National Natural Science Foundation of China (Nos.50772085, 50911120025)
文摘VO2/ordered mesoporous carbon (CMK-3) composites were prepared by solid-state reaction process. The microstructures were characterized by X-ray diffraction (XRD), nitrogen adsorption and desorption, field-emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The experimental results showed that the vanadium oxide in the composites was vanadium dioxide (VO2) with monoclinic structure, which was artificially loaded on the outer surface of CMK-3. VO2/ordered mesoporous carbon composites present a significantly improved capacitive performance (131 F/g) increased by 40.86% compared to that of CMK-3 carbon (93 F/g). Therefore, as-prepared VO2/mesoporous carbon composites suggest promising applications in hybrid capacitors.