Catalytic hydrogenation of CO_(2) using renewable hydrogen not only reduces greenhouse gas emissions,but also provides industrial chemicals.Herein,a Co-Fe bimetallic catalyst was developed by a facile reactive ball-mi...Catalytic hydrogenation of CO_(2) using renewable hydrogen not only reduces greenhouse gas emissions,but also provides industrial chemicals.Herein,a Co-Fe bimetallic catalyst was developed by a facile reactive ball-milling method for highly active and selective hydrogenation of CO_(2) to value-added hydrocarbons.When reacted at 320℃,1.0 MPa and 9600 mL h^(-1) g_(cat)^(-1),the selectivity to light olefin(C_(2)^(=)-C_(4)^(=)) and C_(5)+ species achieves 57.3% and 22.3%,respectively,at a CO_(2) co nversion of 31.4%,which is superior to previous Fe-based catalysts.The CO_(2) activation can be promoted by the CoFe phase formed by reactive ball milling of the Fe-Co_(3)O_(4) mixture,and the in-situ Co_(2)C and Fe_(5)C_(2) formed during hydrogenation are beneficial for the C-C coupling reaction.The initial C-C coupling is related to the combination of CO species with the surface carbon of Fe/Co carbides,and the sustained C-C coupling is maintained by self-recovery of defective carbides.This new strategy contributes to the development of efficient catalysts for the hydrogenation of CO_(2) to value-added hydrocarbons.展开更多
化石燃料的燃烧导致大气中二氧化碳(CO_(2))的浓度迅速上升,并引发了严重的能源、环境危机。由可再生电力驱动的电催化CO_(2)还原为增值化学品和燃料是解决当前化石燃料枯竭的一种有效方法。采用“一锅法”制备了磷(P)修饰的高分散性“...化石燃料的燃烧导致大气中二氧化碳(CO_(2))的浓度迅速上升,并引发了严重的能源、环境危机。由可再生电力驱动的电催化CO_(2)还原为增值化学品和燃料是解决当前化石燃料枯竭的一种有效方法。采用“一锅法”制备了磷(P)修饰的高分散性“钴-氮-碳”(Co-N-C/P)催化剂,通过扫描电子显微镜(SEM)、X射线衍射(XRD)、拉曼光谱(Raman)和X射线光电子能谱(XPS)等手段对催化剂的形貌、元素分布、缺陷程度、表面元素价态及配位结构进行了表征,并考察了其在H型电解槽中电催化CO_(2)还原为CO的性能。测试结果表明,所制备的Co-N-C/P催化剂在-0.9 V vs.RHE的外加电位下具有97.0%的CO法拉第效率(FE_(CO)),电流密度为4.58 mA/cm^(2),并可以进行26 h的稳定性测试。与Co-N-C催化剂相比,P的掺杂更有利于Co原子在碳黑基底上的良好分散,相应的FE_(CO)提高了约38.9%,说明P的掺杂有效提高了Co-N-C催化剂的电催化CO_(2)还原为CO的性能。展开更多
Platinum nanoparticles supported on carbons（Pt/C,60%,mass fraction） electrocatalysts for direct methanol fuel cell（DMFC） were prepared by citrate-stabilized method with different reductants and carbon supports.The...Platinum nanoparticles supported on carbons（Pt/C,60%,mass fraction） electrocatalysts for direct methanol fuel cell（DMFC） were prepared by citrate-stabilized method with different reductants and carbon supports.The catalysts were characterized by X-ray diffraction（XRD）,transmission electron microscopy（TEM） and cyclic voltammetry（CV）.It is found that the size of Pt nanoparticles on carbon is controllable by citrate addition and reductant optimization,and the form of carbon support has a great influence on electrocatalytic activity of catalysts.The citrate-stabilized Pt nanoparticles supported on BP2000 carbon,which was reduced by formaldehyde,exhibit the best performance with about 2 nm in diameter and 66.46 m2/g（Pt） in electrocatalytic active surface（EAS） area.Test on single DMFC with 60%（mass fraction） Pt/BP2000 as cathode electrocatalyst showed maximum power density at 78.8 mW/cm2.展开更多
基金supported by the National Natural Science Foundation of China (22008098, 21978156, 42002040)the Program for Innovative Research Team (in Science and Technology) in University of Henan Province (21IRTSTHN004)+1 种基金the Program for Science & Technology Innovation Talents in Universities of Henan Province (22HASTIT008)the Foundation of State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering (2022-K34)。
文摘Catalytic hydrogenation of CO_(2) using renewable hydrogen not only reduces greenhouse gas emissions,but also provides industrial chemicals.Herein,a Co-Fe bimetallic catalyst was developed by a facile reactive ball-milling method for highly active and selective hydrogenation of CO_(2) to value-added hydrocarbons.When reacted at 320℃,1.0 MPa and 9600 mL h^(-1) g_(cat)^(-1),the selectivity to light olefin(C_(2)^(=)-C_(4)^(=)) and C_(5)+ species achieves 57.3% and 22.3%,respectively,at a CO_(2) co nversion of 31.4%,which is superior to previous Fe-based catalysts.The CO_(2) activation can be promoted by the CoFe phase formed by reactive ball milling of the Fe-Co_(3)O_(4) mixture,and the in-situ Co_(2)C and Fe_(5)C_(2) formed during hydrogenation are beneficial for the C-C coupling reaction.The initial C-C coupling is related to the combination of CO species with the surface carbon of Fe/Co carbides,and the sustained C-C coupling is maintained by self-recovery of defective carbides.This new strategy contributes to the development of efficient catalysts for the hydrogenation of CO_(2) to value-added hydrocarbons.
文摘化石燃料的燃烧导致大气中二氧化碳(CO_(2))的浓度迅速上升,并引发了严重的能源、环境危机。由可再生电力驱动的电催化CO_(2)还原为增值化学品和燃料是解决当前化石燃料枯竭的一种有效方法。采用“一锅法”制备了磷(P)修饰的高分散性“钴-氮-碳”(Co-N-C/P)催化剂,通过扫描电子显微镜(SEM)、X射线衍射(XRD)、拉曼光谱(Raman)和X射线光电子能谱(XPS)等手段对催化剂的形貌、元素分布、缺陷程度、表面元素价态及配位结构进行了表征,并考察了其在H型电解槽中电催化CO_(2)还原为CO的性能。测试结果表明,所制备的Co-N-C/P催化剂在-0.9 V vs.RHE的外加电位下具有97.0%的CO法拉第效率(FE_(CO)),电流密度为4.58 mA/cm^(2),并可以进行26 h的稳定性测试。与Co-N-C催化剂相比,P的掺杂更有利于Co原子在碳黑基底上的良好分散,相应的FE_(CO)提高了约38.9%,说明P的掺杂有效提高了Co-N-C催化剂的电催化CO_(2)还原为CO的性能。
基金Project(50573041)supported by the National Natural Science Foundation of China
文摘Platinum nanoparticles supported on carbons（Pt/C,60%,mass fraction） electrocatalysts for direct methanol fuel cell（DMFC） were prepared by citrate-stabilized method with different reductants and carbon supports.The catalysts were characterized by X-ray diffraction（XRD）,transmission electron microscopy（TEM） and cyclic voltammetry（CV）.It is found that the size of Pt nanoparticles on carbon is controllable by citrate addition and reductant optimization,and the form of carbon support has a great influence on electrocatalytic activity of catalysts.The citrate-stabilized Pt nanoparticles supported on BP2000 carbon,which was reduced by formaldehyde,exhibit the best performance with about 2 nm in diameter and 66.46 m2/g（Pt） in electrocatalytic active surface（EAS） area.Test on single DMFC with 60%（mass fraction） Pt/BP2000 as cathode electrocatalyst showed maximum power density at 78.8 mW/cm2.
