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SO_2存在下钠、钙、铁及其复合物对NO-半焦反应的催化作用(英文) 被引量:1
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作者 李文 常惠 +1 位作者 陈皓侃 李保庆 《燃料化学学报》 EI CAS CSCD 北大核心 2005年第6期656-660,共5页
采用程序升温还原技术,在SO2存在气氛下,对钠、钙、铁及其复合物的NO-半焦催化反应性能进行了研究。结果表明,在相同条件下三种金属对NO-半焦反应的催化活性顺序为:Fe>Ca>Na。SO2可能通过参与氧传递过程来影响金属对NO-半焦反应... 采用程序升温还原技术,在SO2存在气氛下,对钠、钙、铁及其复合物的NO-半焦催化反应性能进行了研究。结果表明,在相同条件下三种金属对NO-半焦反应的催化活性顺序为:Fe>Ca>Na。SO2可能通过参与氧传递过程来影响金属对NO-半焦反应的催化活性。SO2的浓度对负载三种不同金属半焦催化活性的影响是不同的。SO2浓度对负载钠半焦的催化活性影响最为显著。在SO2存在气氛下,负载2%钠或铁和负载3%钙的半焦具有高的NO转化活性。在SO2存在气氛下,钠-钙和钠-铁二元金属复合催化剂的活性较高,这可能是由于这两种金属间存在协同作用的缘故。 展开更多
关键词 NO-半焦反应 SO2 金属催化活性 复合催化
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Progress in research on catalysts for catalytic oxidation of formaldehyde 被引量:38
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作者 拜冰阳 乔琦 +1 位作者 李俊华 郝吉明 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2016年第1期102-122,共21页
Formaldehyde(HCHO)is carcinogenic and teratogenic,and is therefore a serious danger to human health.It also adversely affects air quality.Catalytic oxidation is an efficient technique for removing HCHO.The developme... Formaldehyde(HCHO)is carcinogenic and teratogenic,and is therefore a serious danger to human health.It also adversely affects air quality.Catalytic oxidation is an efficient technique for removing HCHO.The development of highly efficient and stable catalysts that can completely convert HCHO at low temperatures,even room temperature,is important.Supported Pt and Pd catalysts can completely convert HCHO at room temperature,but their industrial applications are limited because they are expensive.The catalytic activities in HCHO oxidation of transition-metal oxide catalysts such as manganese and cobalt oxides with unusual morphologies are better than those of traditional MnO2,Co3O4,or other metal oxides.This is attributed to their specific structures,high specific surface areas,and other factors such as active phase,reducibility,and amount of surface active oxygens.Such catalysts with various morphologies have great potential and can also be used as catalyst supports.The loading of relatively cheap Ag or Au on transition-metal oxides with special morphologies potentially improves the catalytic activity in HCHO removal at room temperature.The preparation and development of new nanocatalysts with various morphologies and structures is important for HCHO removal.In this paper,research progress on precious-metal and transition-metal oxide catalyst systems for HCHO oxidation is reviewed; topics such as oxidation properties,structure–activity relationships,and factors influencing the catalytic activity and reaction mechanism are discussed.Future prospects and directions for the development of such catalysts are also covered. 展开更多
关键词 FORMALDEHYDE Catalytic oxidation Metal oxide catalyst Noble metal catalyst Low-temperature catalytic activity
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Improving the performance of metal-organic frameworks for thermo-catalytic CO_(2)conversion:Strategies and perspectives 被引量:5
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作者 Leiduan Hao Qineng Xia +2 位作者 Qiang Zhang Justus Masa Zhenyu Sun 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2021年第11期1903-1920,共18页
Climate change caused by the increasing emission of CO_(2)to the atmosphere has become a global concern.To ameliorate this issue,converting CO_(2)into valuable chemicals is highly desirable,enabling a sustainable low-... Climate change caused by the increasing emission of CO_(2)to the atmosphere has become a global concern.To ameliorate this issue,converting CO_(2)into valuable chemicals is highly desirable,enabling a sustainable low-carbon future.To this end,developing efficient catalytic systems for CO_(2)conversion has sparked intense interests from both academia and industry.Taking advantage of their highly porous structures and unique properties,metal−organic frameworks(MOFs)have shown great potential as heterogeneous catalysts for CO_(2)conversion.Various transformations involving CO_(2)have been accomplished over MOFs-based materials.Here we provide a comprehensive and up-to-date review on recent advances of heterogeneous CO_(2)thermocatalysis using MOFs,highlighting relationships between structures and properties.Special attention is given to the design strategies for improving the catalytic performance of MOFs.Avenues available to enrich the catalytic active sites in MOF structures are stressed and their respective impacts on CO_(2)conversion efficiency are presented.The synergistic effects between each active site within the structure of MOFs and derivatives are discussed.In the end,future perspectives and challenges in CO_(2)conversion by heterogeneous catalysis with MOFs are described. 展开更多
关键词 CO_(2) conversion Metal-organic frameworks Catalytic active sites SYNERGY Catalytic performance
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Preparation of Photocatalytic TiO_2 and TiO_2-SiO_2 Particles and Application to Degradation of Trace Organics in Aqueous Solution 被引量:2
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作者 周亚松 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2003年第6期665-670,共6页
TiO2 and TiO2-SiO2 photocatalysts were prepared by sol-gel and supercritical CO2 fluid drying method and characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), etc. Their catalytic propertie... TiO2 and TiO2-SiO2 photocatalysts were prepared by sol-gel and supercritical CO2 fluid drying method and characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), etc. Their catalytic properties were tested through the photocatalytic degradation of phenol and aniline in wastewater. The results show that the developed fluidized photocatalytic reactor (FPR) and TiO2 catalyst had better performance in degrading pollutants as compared with slurry photocatalytic reactor (SPR) and commercial TiO2 catalyst. The composition and crystal form of TiO2-SiO2 composite oxide had obvious influence on catalytic effect and TiO2-SiO2 photocatalysts showed better catalytic activity and stability. 展开更多
关键词 titanium dioxide composite oxide photocatalytic activity DEGRADATION
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Doping-induced metal–N active sites and bandgap engineering in graphitic carbon nitride for enhancing photocatalytic H_(2 )evolution performance 被引量:6
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作者 Xiaohui Yu Haiwei Su +3 位作者 Jianping Zou Qinqin Liu Lele Wang Hua Tang 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2022年第2期421-432,共12页
Durable and inexpensive graphitic carbon nitride(g-C_(3)N_(4))demonstrates great potential for achieving efficient photocatalytic hydrogen evolution reduction(HER).To further improve its activity,g-C_(3)N_(4)was subje... Durable and inexpensive graphitic carbon nitride(g-C_(3)N_(4))demonstrates great potential for achieving efficient photocatalytic hydrogen evolution reduction(HER).To further improve its activity,g-C_(3)N_(4)was subjected to atomic-level structural engineering by doping with transition metals(M=Fe,Co,or Ni),which simultaneously induced the formation of metal-N active sites in the g-C_(3)N_(4)framework and modulated the bandgap of g-C_(3)N_(4).Experiments and density functional theory calculations further verified that the as-formed metal-N bonds in M-doped g-C_(3)N_(4)acted as an"electron transfer bridge",where the migration of photo-generated electrons along the bridge enhanced the efficiency of separation of the photogenerated charges,and the optimized bandgap of g-C_(3)N_(4)afforded stronger reduction ability and wider light absorption.As a result,doping with either Fe,Co,or Ni had a positive effect on the HER activity,where Co-doped g-C_(3)N_(4)exhibited the highest performance.The findings illustrate that this atomic-level structural engineering could efficiently improve the HER activity and inspire the design of powerful photocatalysts. 展开更多
关键词 g-C_(3)N_(4) Photocatalytic H_(2)generation Metal-N active sites Transition metal doping Band gap engineering
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Effect of Impregnation Sequence on Propane Dehydrogenation Performance of PtSnNa/ZSM-5 Catalyst 被引量:1
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作者 Liu Hui Zhou Yuming +3 位作者 Zhang Yiwei Sheng Xiaoli Zhang Zewu Zhou Shijiang 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2013年第4期54-62,共9页
The effects of the sequence for impregnation of metal precursors on the performance of PtSnNa/ZSM-5 catalyst for propane dehydrogenation to propene were studied in this paper.Some methods such as XRD,TPDA,BET,H2-TPR,X... The effects of the sequence for impregnation of metal precursors on the performance of PtSnNa/ZSM-5 catalyst for propane dehydrogenation to propene were studied in this paper.Some methods such as XRD,TPDA,BET,H2-TPR,XPS,ICP,TEM and hydrogen chemisorption were used to characterize the catalysts.The structure of ZSM-5 zeolite was not destroyed by the introduction of metal components.Meanwhile the different impregnation sequence of metal precursors could affect the behavior of Sn4+species entering the ZSM-5 channel,and the interaction between platinum and tin species,as well as the degree for reduction of Pt and Sn components.As a result,the prepared catalysts exhibited different reaction activity and selectivity.Compared with the co-impregnation treated catalyst,the catalysts prepared by the sequential impregnation method showed better catalytic activity in propane dehydrogenation,especially the one prepared through impregnation with tin precursor at first.Finally,a model for the effect of impregnation sequence on the distribution of Pt and Sn species in PtSnNa/ZSM-5 catalyst was proposed. 展开更多
关键词 impregnation sequence propane dehydrogenation PtSnNa/ZSM-5 PROPENE
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Reversible transformation between terrace and step sites of Pt nanoparticles on titanium under CO and O_(2) environments
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作者 Yang Ou Songda Li +5 位作者 Fei Wang Xinyi Duan Wentao Yuan Hangsheng Yang Ze Zhang Yong Wang 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2022年第8期2026-2033,共8页
Understanding the dynamic evolution of active sites of supported metal catalysts during catalysis is fundamentally important for improving its performance,which attracts tremendous research interests in the past decad... Understanding the dynamic evolution of active sites of supported metal catalysts during catalysis is fundamentally important for improving its performance,which attracts tremendous research interests in the past decades.There are two main surficial structures for metal catalysts:terrace sites and step sites,which exhibit catalytic activity discrepancy during catalysis.Herein,by using in situ transmission electron microscopy and in situ Fourier transform infrared spectroscopy(FTIR),the transformation between surface terrace and step sites of Pt-TiO_(2) catalysts was studied under CO and O_(2) environments.We found that the{111}step sites tend to form at{111}terrace under O_(2) environment,while these step sites prefer to transform into terrace under CO environment at elevated temperature.Meanwhile,quantitative ratios of terrace/step sites were obtained by in situ FTIR.It was found that this transformation between terrace sites and step sites was reversible during gas treatment cycling of CO and O_(2).The selective adsorption of O_(2) and CO species at different sites,which stabilized the step/terrace sites,was found to serve as the driving force for active sites transition by density functional theory calculations.Inspired by the in situ results,an enhanced catalytic activity of Pt-TiO_(2) catalysts was successfully achieved through tuning surface-active sites by gas treatments. 展开更多
关键词 In situ transmission electron microscopy Surface reconstruction Metal catalyst Active site CO oxidation reaction
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Top-down synthesis strategies: Maximum noble-metal atom efficiency in catalytic materials 被引量:1
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作者 Yaxin Chen Zhiwei Huang +3 位作者 Xiao Gu Zhen Ma Jianmin Chen Xingfu Tang 《Chinese Journal of Catalysis》 CSCD 北大核心 2017年第9期1588-1596,共9页
Top‐down synthesis has been used to prepare catalytic materials with nanometer sizes,but fabricating atomically dispersed metal catalysts remains a challenge because surface single metal atoms are prone to aggregatio... Top‐down synthesis has been used to prepare catalytic materials with nanometer sizes,but fabricating atomically dispersed metal catalysts remains a challenge because surface single metal atoms are prone to aggregation or coalescence.A top‐down strategy is used to synthesize atomically dispersed metal catalysts,based on supported Ag nanoparticles.The changes of the geometric and electronic structures of the Ag atoms during the top‐down process are studied using the in situ synchrotron X‐ray diffraction technique,ex situ X‐ray absorption spectroscopy,and transmission electron microscopy.The experimental results,coupled with the density functional theory calculations,demonstrate that the electronic perturbation of the Ag frontier orbitals,induced by the Ag‐O interactions at the perimeter of the metal‐support interface,is the driving force of the top‐down process.The top‐down synthesis has two important functions:to increase the number of catalytic active sites and to facilitate the study of complex reaction mechanisms(e.g.,formaldehyde oxidation)by developing single‐site model catalysts. 展开更多
关键词 Top‐down synthesis Atomic dispersion Catalytic active site Electronic metal‐support interaction Formaldehyde oxidation
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Study on the Effect of Catalyst Properties on Residue Hydroconversion 被引量:1
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作者 Tong Fengya Yang Qinghe +2 位作者 Li Dadong Dai Lishun Deng Zhonghuo 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2016年第1期1-7,共7页
The effect of catalyst properties on residue oil hydroconversion was studied at moderate operating conditions(at a temperature of 400 ℃, an initial hydrogen pressure of 10 MPa, and a reaction time of 4 h) in a batch ... The effect of catalyst properties on residue oil hydroconversion was studied at moderate operating conditions(at a temperature of 400 ℃, an initial hydrogen pressure of 10 MPa, and a reaction time of 4 h) in a batch mode slurry phase with different catalyst samples. The results showed that the catalyst acidity had a good effect on residue conversion and MCR(micro carbon residue) conversion but brought about higher coke yield. Residue conversion was thermally induced but the catalyst acidity changed its conversion route. A catalyst with higher metal loading, higher hydrogenation activity and appropriate pore size had higher sulfur and metal removal rate, higher MCR conversion and also a lower coke formation. The activity of spent commercial catalyst AS1 and DS1 was slightly lower than the corresponding fresh ones but was still high enough for residue oil hydroconversion. It assumes that the role of the catalyst is to activate hydrogen species toward reaction with an aromatic carbon radical to yield a cyclohexadienyl type intermediate which will turn into liquid and also to absorb the mesophase which can easily aggregate to form coke. 展开更多
关键词 residue oil hydroconversion catalyst slurry phase mechanism
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Catalytic Oxidative Desulfurization of Gasoline Using Vanadium(V)-substituted Polyoxometalate/H_2O_2/Ionic Liquid Emulsion System 被引量:2
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作者 Ge Jianhua Zhou Yuming +1 位作者 Yang Yong Xue Mengwei 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2012年第1期25-31,共7页
Aiming at deep desulfurization of gasoline,three amphiphilic catalysts [C18H37N(CH3)3]3+x [PMo12-xVxO40](x=1,2,or 3) were prepared and characterized.The amphiphilic vanadium(V)-substituted polyoxometalates were dissol... Aiming at deep desulfurization of gasoline,three amphiphilic catalysts [C18H37N(CH3)3]3+x [PMo12-xVxO40](x=1,2,or 3) were prepared and characterized.The amphiphilic vanadium(V)-substituted polyoxometalates were dissolved in water-immiscible ionic liquid([Bmim]PF6),forming a H2O2-in-[Bmim]PF6 emulsion desulfurization system with 30 m% H2O2 serving as the oxidant.The catalytic oxidation of sulfur-containing model oil has been studied in detail under various reaction conditions using this system.The ionic liquid emulsion system showed high catalytic oxidative activity in the treatment of commodity gasoline.Furthermore,the mechanism of catalytic oxidative desulfurization was also elaborated. 展开更多
关键词 DESULFURIZATION vanadium (V)-substituted polyoxometalates ionic liquid emulsion catalytic oxidation
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STUDIES ON THE CATALYTIC REACTION OF NITROGEN OXIDE ON METAL MODIFIED ACTIVATED CARBON FIBERS
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作者 FURuowen DUXiuying +2 位作者 LINYuansheng XUHao HUYiongjun 《Chinese Journal of Reactive Polymers》 2003年第1期17-25,共9页
The catalytic reaction of NO with CO and decomposition of NO over metal modified ACFs were investigated and compared with other carriers supported catalysts. It is demonstrated that Pd/ACF and Pd/Cu/ACF have high cata... The catalytic reaction of NO with CO and decomposition of NO over metal modified ACFs were investigated and compared with other carriers supported catalysts. It is demonstrated that Pd/ACF and Pd/Cu/ACF have high catalytic activity for the reaction of NO/CO, while Pt/ACF, Pt/Cu/ACF and Co/Cu/ACF have very low catalytic activity in similar circumstance. Pd-modified ACF possesses high catalytic decomposition of NO at 300℃. Pd/CB and Pd/GAC present good catalytic decomposition ability for NO only at low flowrate. Pd/G, Pd/ZMS and Pd/A however, do not show any catalytic activity for NO decomposition even at 400℃. Catalytic temperature, NO flowrate and loading of metal components affect the decomposition rate of NO. The coexistence of Cu with Pd on Cu/Pd/ACF leads to crystalline of palladium to more unperfected so as to that increase the catalytic activity. 展开更多
关键词 Activated carbon fiber PALLADIUM Catalytic reduction Catalytic decomposition Nitrogen monoxide
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STUDY ON THE CATALYTIC ABILITY OF BIOACTIVE FIBERS
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作者 YAO Yuyuan CHEN Wenxing 《Chinese Journal of Reactive Polymers》 2006年第1期40-44,共5页
Two kinds of water-soluble metallophthalocyanines (Mt2Pc2), binuclear cobalt phthalocyanine (Co2Pc2) and binuclear ferric phthalocyanine (Fe2Pc2), were supported on silk fibers and modified viscose fibers to con... Two kinds of water-soluble metallophthalocyanines (Mt2Pc2), binuclear cobalt phthalocyanine (Co2Pc2) and binuclear ferric phthalocyanine (Fe2Pc2), were supported on silk fibers and modified viscose fibers to construct bioactive fibers of mimic enzyme, Mt2Pc2 used as the active center of bioactive fibers, viscose and silk fibers as the microenvironments. The catalytic oxidation ability of bioactive fibers on the malodors of methanthiol and hydrogen sulfide was investigated at room temperature. The experimental results demonstrated that the catalytic activity of such bioactive fibers was tightly correlative to the types of bioactive fibers and substrates. 展开更多
关键词 Silk fibers Viscose fibers Bioactive fibers METALLOPHTHALOCYANINE Catalytic oxidation.
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PdPb bimetallic nanowires as electrocatalysts for enhanced ethanol electrooxidation 被引量:3
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作者 Ning Ma Shuqing Wang +4 位作者 Xuehua Liu Yunchang Sun Yanru Yin Lian Ying Zhang Peizhi Guo 《Science China Materials》 SCIE EI CSCD 2020年第10期2040-2049,共10页
Less-expensive but efficient electrocatalysts are essential to accelerate the commercialization of fuel cells.Herein,ultrathin PdPb nanowires(PdPb NWs)with a diameter of around 3.5 nm were prepared by using a one-step... Less-expensive but efficient electrocatalysts are essential to accelerate the commercialization of fuel cells.Herein,ultrathin PdPb nanowires(PdPb NWs)with a diameter of around 3.5 nm were prepared by using a one-step hydrothermal method.The introduction of Pb in Pd-based bimetallic nanostructures produced high differences in the morphology from Pd nanoparticles(NPs)to various PdPb NWs.All the as-prepared PdPb NWs exhibited better electrocatalytic activity and durability than Pd NPs due to the synergistic effect.Especially,Pd65Pb35 possessed the highest current density of about 3460 mA mgPd^−1 for the ethanol electrooxidation which was around 6.3 times higher than commercial Pd/C.The high-performance of Pd65Pb35 is attributed to the defect-rich and stable nanowire structure with optimized surface atomic arrangement,as evidenced by high resolution transmission electron microscopy measurements and long-time treatment in an acidic media.The differences in the morphologies and electrocatalytic activities of PdPb NWs with varied Pb contents have also been discussed and analyzed. 展开更多
关键词 PdPb nanowires electronic structure lattice defects ELECTROCATALYSIS ethanol electrooxidation
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Melamine-assisted synthesis of ultrafine Mo_(2)C/Mo_(2)N@N-doped carbon nanofibers for enhanced alkaline hydrogen evolution reaction activity 被引量:6
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作者 Jing Chen Anqiang Pan +4 位作者 Wenchao Zhang Xinxin Cao Rou Lu Shuquan Liang Guozhong Cao 《Science China Materials》 SCIE EI CAS CSCD 2021年第5期1150-1158,共9页
Noble metal-free electrocatalysts with high activity are highly desirable for the large-scale application of hydrogen evolution reaction(HER). Mo_(2) C-based nanomaterials have been proved as a promising alternative t... Noble metal-free electrocatalysts with high activity are highly desirable for the large-scale application of hydrogen evolution reaction(HER). Mo_(2) C-based nanomaterials have been proved as a promising alternative to noble metal-based electrocatalysts owing to the Pt-resembled d-band density and optimal intermediates-adsorption properties.However, the aggregation and excessive growth of crystals often occur during their high-temperature synthesis procedure, leading to low catalytic utilization. In this study, the ultrafine Mo_(2) C/Mo_(2) N heterostructure with large surface and interface confined in the N-doped carbon nanofibers(NCNFs) was obtained by a melamine-assisted method. The synergistic effect of Mo_(2) C/Mo_(2) N heterostructure and plenty active sites exposed on the surface of ultrafine nanocrystals improves the electrocatalytic activity. Meanwhile, the N-CNFs ensure fast charge transfer and high structural stability during reactions. Moreover, the in-situ synthesis method strengthens the interfacial coupling interactions between Mo_(2)C/Mo_(2) N heterostructure and N-CNFs, further enhancing the electronic conductivity and electrocatalytic activity. Owing to these advantages, Mo_(2)C/Mo_(2) N@N-CNFs exhibit excellent HER performance with a low overpotential of 75 mV at a current density of 10 mV cm^(-2) in alkaline solution, superior to the single-phased Mo_(2)C counterpart and recently reported Mo_(2)C/Mo_(2) N-based catalysts. This study highlights a new effective strategy to design efficient electrocatalysts via integrating heterostructure, nanostructure and carbon modification. 展开更多
关键词 Mo2C hydrogen evolution reaction HETEROSTRUCTURE ULTRAFINE NANOFIBERS
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A highly-efficient oxygen evolution electrode based on defective nickel-iron layered double hydroxide 被引量:9
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作者 Xuya Xiong Zhao Cai +10 位作者 Daojin Zhou Guoxin Zhang Qian Zhang Yin Jia Xinxuan Duan Qixian Xie Shibin Lai Tianhui Xie Yaping Li Xiaoming Sun Xue Duan 《Science China Materials》 SCIE EI CSCD 2018年第7期939-947,共9页
Exploring efficient and cost-effective electro- catalysts for oxygen evolution reaction (OER) is critical to water splitting. While nickel-iron layered double hydroxide (NiFe LDH) has been long recognized as a pro... Exploring efficient and cost-effective electro- catalysts for oxygen evolution reaction (OER) is critical to water splitting. While nickel-iron layered double hydroxide (NiFe LDH) has been long recognized as a promising non- precious electrocatalyst for OER, its intrinsic activity needs further improvement. Herein, we design a highly-efficient oxygen evolution electrode based on defective NiFe LDH na- noarray. By combing the merits of the modulated electronic structure, more exposed active sites, and the conductive elec- trode, the defective NiFe LDH electrocatalysts show a low onset potential of 1.40 V (vs. RHE). An overpotential of only 200 mV is required for 10 mA cm-2, which is 48 mV lower than that of pristine NiFe-LDH. Density functional theory plus U (DFT+U) calculations are further employed for the origin of this OER activity enhancement. We find the introduction of oxygen vacancies leads to a lower valance state of Fe and the narrowed bandgap, which means the electrons tend to be ea- sily excited into the conduction band, resulting in the lowered reaction overpotential and enhanced OER performance. 展开更多
关键词 oxygen evolution reaction layered double hydroxide oxygen vacancy ELECTROCATALYSIS
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Reductive amination of 1,6-hexanediol with Ru/Al2O3 catalyst in supercritical ammonia 被引量:7
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作者 Yan Li Haiyang Cheng +6 位作者 Chao Zhang Bin Zhang Tong Liu Qifan Wu Xinluona Su Weiwei Lin Fengyu Zhao 《Science China Chemistry》 SCIE EI CAS CSCD 2017年第7期920-926,共7页
Hexamethylenediamine(HMDA) is an important reagent for the synthesis of Nylon-6,6, and it is usually produced by the hydrogenation of adiponitrile using a toxic reagent of hydrocyanic acid. Herein, we developed an env... Hexamethylenediamine(HMDA) is an important reagent for the synthesis of Nylon-6,6, and it is usually produced by the hydrogenation of adiponitrile using a toxic reagent of hydrocyanic acid. Herein, we developed an environmental friendly route to produce HMDA via catalytic reductive amination of 1,6-hexanediol(HDO) in the presence of hydrogen. The activities of several heterogeneous metal catalysts such as supported Ni, Co, Ru, Pt, Pd catalysts were screened for the present reaction in supercritical ammonia without any additives. Among the catalysts examined, Ru/Al_2O_3 presented a high catalytic activity and highest selectivity for the desired product of HMDA. The high performance of Ru/Al_2O_3 was discussed based on the Ru dispersion and the surface properties like the acid-basicity. In addition, the reaction parameters such as reaction temperature,time, H_2 and NH_3 pressure were examined, and the reaction processes were discussed in detail. 展开更多
关键词 1 6-hexanediol hexamethylenediamine supercritical ammonia reductive amination Ru/Al2O3
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Facile synthesis of Fe/Ni bimetallic oxide solid-solution nanoparticles with superior electrocatalytic activity for oxygen evolution reaction 被引量:13
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作者 Lingxiao Wang Jing Geng Wenhai Wang Chao Yuan Long Kuai Baoyou Geng 《Nano Research》 SCIE EI CAS CSCD 2015年第12期3815-3822,共8页
The sluggish oxygen evolution reaction (OER) is an important half-reaction of the electrochemical water-splitting reaction. Amorphous Fe/Ni composite oxides have high activity. In this work, we modified the aerosol ... The sluggish oxygen evolution reaction (OER) is an important half-reaction of the electrochemical water-splitting reaction. Amorphous Fe/Ni composite oxides have high activity. In this work, we modified the aerosol spray-assisted approach and obtained amorphous Fe-Ni-Ox solid-solution nanoparticles (Fe-Ni-Ox-NPs) approximately 20 nm in size by choosing iron/nickel acetylacetonates as raw materials instead of inorganic salts. The small-sized Fe-Ni-Ox-NPs were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) analysis, energy-dispersive X-ray spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS). Furthermore, an investigation of electrochemical OER performance suggests that the small-sized Fe-Ni-Ox-NPs have higher activity than the large-sized Fe-Ni-Ox-MPs. A small overpotential of 0.315 V was demanded to obtain a working current density of 50 mA/cm2, and the Tafel slope was as low as 38 mWdec. 展开更多
关键词 Fe-Ni-Ox solid solution ELECTROCATALYSIS oxygen evolution reaction
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Facile fabrication of CdS-metal-organic framework nanocomposites with enhanced visible-light photocatalytic activity for organic transformation 被引量:7
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作者 Fei Ke LuhuanWang Junfa Zhu 《Nano Research》 SCIE EI CAS CSCD 2015年第6期1834-1846,共13页
Visible-light-initiated organic transformations have received much attention because of low cost, relative safety, and environmental friendliness. In this work, we report on a novel type of visible-light-driven photoc... Visible-light-initiated organic transformations have received much attention because of low cost, relative safety, and environmental friendliness. In this work, we report on a novel type of visible-light-driven photocatalysts, namely, porous nanocomposites of CdS-nanoparticle-decorated metal-organic frameworks (MOF), prepared by a simple solvothermal method in which porous MIL-100(Fe) served as the support and cadmium acetate (Cd(Ac)2) as the CdS precursor. When the selective oxidation of benzyl alcohol to benzaldehyde is used as the probe reaction, the results show that the combination of MIL-100(Fe) and CdS semiconductor can remarkably enhance the photocatalytic efficiency at room temperature, as compared to that of pure CdS. The enhanced photocatalytic performance can be attributed to the combined effects of enhanced light absorption, more efficient separation of photogenerated electron-hole pairs, and increased surface area of CdS due to the presence of MIL-100(Fe). This work demonstrates that MOF-based composite materials hold great promise for applications in the field of solar-energy conversion into chemical energy. 展开更多
关键词 metal-organicframeworks porous materials NANOCOMPOSITES PHOTOCATALYSIS semiconductors
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Core@shell sub-ten-nanometer noble metal nanoparticles with a controllable thin Pt shell and their catalytic activity towards oxygen reduction 被引量:4
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作者 Ntirikwendera Deogratias Muwei Ji +3 位作者 Yong Zhang Jiajia Liu Jiatao Zhang Hesun Zhu 《Nano Research》 SCIE EI CAS CSCD 2015年第1期271-280,共10页
Reducing Pt loading, while improving electrocatalytic activity and the stability of Pt-based nanostructured materials, is currently a key challenge in green energy technology. Herein, we report the controllable synthe... Reducing Pt loading, while improving electrocatalytic activity and the stability of Pt-based nanostructured materials, is currently a key challenge in green energy technology. Herein, we report the controllable synthesis of tri-metallic (Au@Ag@Pt) and bimetallic (Ag@Pt) particles consisting of a controllable thin Pt shell, via interface-mediated galvanic displacement. Through oil-ethanol-H2O interface mediation, the controllable "out to in" displacement of Ag atoms to Pt enables the formation of a thin Pt shell on monodisperse sub-ten-nanometer Au@Ag and Ag nanocrystals. The synthesized nanoparticles with a thin Pt shell exhibited potential catalytic activity towards the oxygen reduction reaction (ORR) due to the high exposure of Pt atoms. 展开更多
关键词 core@shelLmetal nanocomposites Pt shellsub-ten-nanometer oxygen reduction
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Carbon-CeO interface confinement enhances the chemical stability of Pt nanocatalyst for catalytic oxidation reactions 被引量:2
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作者 Changjin Xu Yue Zhang +3 位作者 Jing Chen Song Li Ya-Wen Zhang Gaowu Qin 《Science China Materials》 SCIE EI CSCD 2021年第1期128-136,共9页
Noble metals are downsized to nano-/subnanoscale to improve their catalytic activity and atom-economy.However,the stabilities in chemical state and catalytic performance of these nanocatalysts often suffer during hars... Noble metals are downsized to nano-/subnanoscale to improve their catalytic activity and atom-economy.However,the stabilities in chemical state and catalytic performance of these nanocatalysts often suffer during harsh conditions.For Pt nanoparticles(NPs)supported on CeO2,activated oxygen diffused from the support over-stabilizes the active sites of Pt,degrading its performance at mild temperature.In this work,Pt nanocatalysts with unique structure of triple-junction are synthesized by selectively growing Pt NPs on the carbon-CeO2 interface.Impressively,the Pt NPs exhibit much enhanced catalytic stability and high activity for CO oxidation at mild temperature.The enhancement is attributed to electron donation from graphitized carbon and the confinement effect from the high-density nanopores of the CeO2 support.The triple-junction of Pt-C-CeO2,combining the merits of CeO2 for activating O2 and electron donating capability of carbon,provides new inspiration to the fabrication of high-performance nanocatalysts. 展开更多
关键词 catalyst stability Pt nanocatalyst interface confinement
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