As a catalyst of the air cathode in zinc-air batteries,tungstic acid ferrous(FeWO_(4)),a nanoscale transition metal tungstate,shows a broad application prospect in the oxygen reduction reaction(ORR).While FeWO_(4)poss...As a catalyst of the air cathode in zinc-air batteries,tungstic acid ferrous(FeWO_(4)),a nanoscale transition metal tungstate,shows a broad application prospect in the oxygen reduction reaction(ORR).While FeWO_(4)possesses favorable electrochemical properties and thermodynamic stability,its intrinsic semiconductor characteristics result in a relatively slow electron transfer rate,limiting the ORR catalytic activity.In this work,the electronic structure of FeWO_(4)is significantly modulated by introducing phosphorus(P)atoms with abundant valence electrons.The P doping can adjust the electronic structure of FeWO_(4)and then optimize oxygen-containing intermediates'absorption/desorption efficiency to achieve improved ORR activity.Furthermore,the sodium chloride template is utilized to construct a porous carbon framework for anchoring phosphorus-doped iron tungstate(P-FeWO_(4)/PNC).The porous carbon skeleton provides numerous active sites for the absorption/desorption and redox reactions on the P-FeWO_(4)/PNC surface and serves as mass transport channels for reactants and intermediates.The P-FeWO_(4)/PNC demonstrates ORR performance(E1/2=0.86 V vs.RHE).Furthermore,the zinc-air batteries incorporating the P-FeWO_(4)/PNC composite demonstrate an increased peak power density(172.2 mW·cm^(-2)),high specific capacity(810.1 mAh·g^(-1)),and sustained long-term cycling stability lasting up to 240 h.This research not only contributes to the advancement of cost-effective tungsten-based non-precious metallic ORR catalysts,but also guides their utilization in zinc-air batteries.展开更多
Emission of volatile organic compounds has important influence on complex air pollution and human health.In this paper,a series of tungsten-iron composite oxides with different proportions and preparation methods were...Emission of volatile organic compounds has important influence on complex air pollution and human health.In this paper,a series of tungsten-iron composite oxides with different proportions and preparation methods were synthesized and first used for catalytic combustion of chlorobenzene and toluene,as typical polluting gas sources.These WO_(3)-based solid catalytic materials were systematically characterized by modern analytical methods,and the results showed that there was strong electron interaction between W and Fe elements in the composite oxides,and the presence of a certain amount of tungsten oxide inhibited the crystallization of iron oxide,and vice versa,which were beneficial to the uniform dispersion of tungsten-iron components into each other and the improvement of redox properties.Compared with single-component oxide,the formation of tungsten-iron composite oxide affected the micro-structure,improved the specific surface area and optimized the pore structure of materials.The performance test results showed that the tungsten-iron composite oxide(FeWO_4-0.5 Fe_(2)O_(3),molar ratio of tungsten and iron was 1/2)prepared using citric acid-based sol-gel method was the optimal,and its catalytic degradation efficiency could reach 90%for chlorobenzene and 83%for toluene at 320℃,and maintain at least 60 h without obvious deactivation,with high selectivity to the formation of HCl and CO_(2).展开更多
基金supported by the National Natural Science Foundation of China(NSFC)(Nos.22178148 and 22278193)a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘As a catalyst of the air cathode in zinc-air batteries,tungstic acid ferrous(FeWO_(4)),a nanoscale transition metal tungstate,shows a broad application prospect in the oxygen reduction reaction(ORR).While FeWO_(4)possesses favorable electrochemical properties and thermodynamic stability,its intrinsic semiconductor characteristics result in a relatively slow electron transfer rate,limiting the ORR catalytic activity.In this work,the electronic structure of FeWO_(4)is significantly modulated by introducing phosphorus(P)atoms with abundant valence electrons.The P doping can adjust the electronic structure of FeWO_(4)and then optimize oxygen-containing intermediates'absorption/desorption efficiency to achieve improved ORR activity.Furthermore,the sodium chloride template is utilized to construct a porous carbon framework for anchoring phosphorus-doped iron tungstate(P-FeWO_(4)/PNC).The porous carbon skeleton provides numerous active sites for the absorption/desorption and redox reactions on the P-FeWO_(4)/PNC surface and serves as mass transport channels for reactants and intermediates.The P-FeWO_(4)/PNC demonstrates ORR performance(E1/2=0.86 V vs.RHE).Furthermore,the zinc-air batteries incorporating the P-FeWO_(4)/PNC composite demonstrate an increased peak power density(172.2 mW·cm^(-2)),high specific capacity(810.1 mAh·g^(-1)),and sustained long-term cycling stability lasting up to 240 h.This research not only contributes to the advancement of cost-effective tungsten-based non-precious metallic ORR catalysts,but also guides their utilization in zinc-air batteries.
基金financially supported by the Zhejiang Provincial Natural Science Foundation(Grant No.LQ19B030004)the National Natural Science Foundation of China(NSFC,Grant Nos.21906106 and 21808048)the soft science research project of Shaoxing Association of Science and Technology。
文摘Emission of volatile organic compounds has important influence on complex air pollution and human health.In this paper,a series of tungsten-iron composite oxides with different proportions and preparation methods were synthesized and first used for catalytic combustion of chlorobenzene and toluene,as typical polluting gas sources.These WO_(3)-based solid catalytic materials were systematically characterized by modern analytical methods,and the results showed that there was strong electron interaction between W and Fe elements in the composite oxides,and the presence of a certain amount of tungsten oxide inhibited the crystallization of iron oxide,and vice versa,which were beneficial to the uniform dispersion of tungsten-iron components into each other and the improvement of redox properties.Compared with single-component oxide,the formation of tungsten-iron composite oxide affected the micro-structure,improved the specific surface area and optimized the pore structure of materials.The performance test results showed that the tungsten-iron composite oxide(FeWO_4-0.5 Fe_(2)O_(3),molar ratio of tungsten and iron was 1/2)prepared using citric acid-based sol-gel method was the optimal,and its catalytic degradation efficiency could reach 90%for chlorobenzene and 83%for toluene at 320℃,and maintain at least 60 h without obvious deactivation,with high selectivity to the formation of HCl and CO_(2).
