The accessibility and mass transfer between catalytic sites and substrates/intermediates are essential to a catalyst's overall performance in oxygen electrocatalysis based energy devices.Here,we present an“in-sit...The accessibility and mass transfer between catalytic sites and substrates/intermediates are essential to a catalyst's overall performance in oxygen electrocatalysis based energy devices.Here,we present an“in-situ self-sacrifice template etching strategy”for reconstructing MOF-derived M-N-C catalysts,which introduces micro-meso-macro pores with continuous apertures in a wide range and a central hollowout structure to optimize the electrochemical oxygen redox kinetics.It is realized via one-step pyrolysis of ZIF-8 single crystal epitaxially coating on a multi-functional template of the Fe,Co co-loaded mesoporous ZnO sphere.The ZnO core is reduced during the general pyrolysis of ZIF-8 into M-N-C and acts as a pore former to etch the surrounding ZIF-8 shell into diverse channels anchoring highly exposed Fe and Co-based active sites with edge enrichment.The redesigned catalyst reveals apparent structural benefits towards enhanced oxygen redox kinetics as bifunctional cathode catalysts of rechargeable zinc-air battery compared with the primitive bulk M-N-C catalysts and the mixture of commercial Pt/C and Ir/C.The unique structure-based activity advantages,the omitted template removal step and good template compatibility during synthesis make the strategy universal for the channel engineering of electrocatalysts.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.51922008,52072114 and 51872075)the 111 Project(No.D17007)+1 种基金Henan Center for Outstanding Overseas Scientists(No.GZS2022017)Xinxiang Major Science and Technology Projects(No.21ZD001)。
文摘The accessibility and mass transfer between catalytic sites and substrates/intermediates are essential to a catalyst's overall performance in oxygen electrocatalysis based energy devices.Here,we present an“in-situ self-sacrifice template etching strategy”for reconstructing MOF-derived M-N-C catalysts,which introduces micro-meso-macro pores with continuous apertures in a wide range and a central hollowout structure to optimize the electrochemical oxygen redox kinetics.It is realized via one-step pyrolysis of ZIF-8 single crystal epitaxially coating on a multi-functional template of the Fe,Co co-loaded mesoporous ZnO sphere.The ZnO core is reduced during the general pyrolysis of ZIF-8 into M-N-C and acts as a pore former to etch the surrounding ZIF-8 shell into diverse channels anchoring highly exposed Fe and Co-based active sites with edge enrichment.The redesigned catalyst reveals apparent structural benefits towards enhanced oxygen redox kinetics as bifunctional cathode catalysts of rechargeable zinc-air battery compared with the primitive bulk M-N-C catalysts and the mixture of commercial Pt/C and Ir/C.The unique structure-based activity advantages,the omitted template removal step and good template compatibility during synthesis make the strategy universal for the channel engineering of electrocatalysts.
