摘要
Amorphous catalysts,thanks to their uniquely coordinated unsaturated properties and abundance of defect sites,tend to possess higher activity and selectivity than their crystalline counterparts.In this work,we report a facile and general solventcontrolled precipitation method to prepare hybrids of graphene oxide(GO)supporting amorphous metal hydroxide[A-M(OH)_(x)/GO,M=Cu,Co,and Mn],which provides us with tangible materials to study the structure–performance relationship of various amorphous oxides.The systematic investigation of A-Cu(OH)_(2)/GO by coupling ex situ/in situ characteristic techniques with electrochemical studies reveals that electrocatalytic activity and selectivity toward a two-electron oxygen reduction reaction(ORR)is highly dependent on the coordinated Cu catalytic sites and the disordered structure of A-Cu(OH)_(2).In situ X-ray absorption near-edge structure(XANES)and density functional theory(DFT)calculation verify that the degree of OH*poisoning(ΔG0 OH*)tuned by three-OH-coordinated Cu sites in amorphous structures plays a crucial role in selective catalysis of ORR for H_(2)O_(2) production.The optimized A-Cu(OH)_(2)/GO shows superior activity and high selectivity(~95%)toward H_(2)O_(2),as demonstrated by a zinc–air battery capable of on-site H_(2)O_(2) production with a rate as high as 3401.5 mmol h^(−1) g^(−1).
基金
the Natural Science Foundation of Fujian Province,China(grant no.2020J05079)
the National Natural Science Foundation of China(grant nos.21875253,21701175,and 21703248)
CAS-Commonwealth Scientific and Industrial Research Organization(CSIRO)Joint Research Projects(no.121835KYSB20200039)
the Scientific Research and Equipment Development Project of CAS(no.YJKYYQ20190007).