Single metal atoms immobilized on a carbon substrate are of great potential for enhancing the catalytic activities for oxygen reduction and methanol oxidation reactions(ORR/MOR)owing to the maximized atom utilization....Single metal atoms immobilized on a carbon substrate are of great potential for enhancing the catalytic activities for oxygen reduction and methanol oxidation reactions(ORR/MOR)owing to the maximized atom utilization.Herein,single copper atoms(SCAs)are loaded on macro-porous nitrogen-doped carbon(Cu-NC)derived from zeolitic imidazolate framework-8(ZIF-8),which are used as catalysts for ORR and Pt-supports for MOR.For ORR,the catalyst marked as Cu-NC-3 exhibits a higher peak potential of 0.87 V(vs.Reversible hydrogen electrode)than that of commercial Pt/C(0.83 V),mainly attributing to that the 3D macro-porous structure of Cu-NC-3 provides adequate space for uniform dispersion of SCAs as the main active species,and smooth diffusion pathways for fast transport of substances(O_(2),H_(2)O),therefore reducing the overpotential and the intermediate(H_(2)O_(2))generation to enhance ORR activity.For MOR,Pt-Cu-NC-3 has a higher mass activity of 1217.4 mA/mg Pt than that of Pt/C(752.4 mA/mg Pt),and its activity maintenance(decline of 27.6%)is also better than Pt/C(decline of 44.0%)after 5000 cyclic voltammetry(CV)cycles.The interactions between SCAs and Pt nanoparticles should facilitate the generation of OH−from water molecules,which can fast eliminate the adsorbed CO to recover the Pt active sites to improve MOR performance.This synthesis strategy affords a new inspiration to prepare single metal atoms loaded on ZIFs-derived macro-structure with diverse activities for ORR/MOR.展开更多
基金support by the National Natural Science Foundation of China(Nos.52070074,21806031 and 51578218)Longjiang Scholars Program(No.Q201912)the Open Project of State Key Laboratory of Urban Water Resource and Environment,Harbin Institute of Technology(No.HC202144).
文摘Single metal atoms immobilized on a carbon substrate are of great potential for enhancing the catalytic activities for oxygen reduction and methanol oxidation reactions(ORR/MOR)owing to the maximized atom utilization.Herein,single copper atoms(SCAs)are loaded on macro-porous nitrogen-doped carbon(Cu-NC)derived from zeolitic imidazolate framework-8(ZIF-8),which are used as catalysts for ORR and Pt-supports for MOR.For ORR,the catalyst marked as Cu-NC-3 exhibits a higher peak potential of 0.87 V(vs.Reversible hydrogen electrode)than that of commercial Pt/C(0.83 V),mainly attributing to that the 3D macro-porous structure of Cu-NC-3 provides adequate space for uniform dispersion of SCAs as the main active species,and smooth diffusion pathways for fast transport of substances(O_(2),H_(2)O),therefore reducing the overpotential and the intermediate(H_(2)O_(2))generation to enhance ORR activity.For MOR,Pt-Cu-NC-3 has a higher mass activity of 1217.4 mA/mg Pt than that of Pt/C(752.4 mA/mg Pt),and its activity maintenance(decline of 27.6%)is also better than Pt/C(decline of 44.0%)after 5000 cyclic voltammetry(CV)cycles.The interactions between SCAs and Pt nanoparticles should facilitate the generation of OH−from water molecules,which can fast eliminate the adsorbed CO to recover the Pt active sites to improve MOR performance.This synthesis strategy affords a new inspiration to prepare single metal atoms loaded on ZIFs-derived macro-structure with diverse activities for ORR/MOR.
