Facile grafting strategy synthesis of single-atom electrocatalyst with enhanced ORR performance

摘要

Single-atom catalysts(SACs)have become one of the most considered research directions today,owing to their maximum atom utilization and simple structures,to investigate structure-activity relationships.In the field of non-precious-metal electrocatalysts,atomically dispersed Fe-N4 active sites have been proven to possess the best oxygen reduction activity.Yet the majority of preparation methods remains complex and costly with unsatisfying controllability.Herein,we have designed a surface-grafting strategy to directly synthesize an atomically dispersed Fe-NVC electrocatalyst applied to the oxygen reduction reaction(ORR).Through an esterification process in organic solution,metal-containing precursors were anchored on the surface of carbon substrates.The covalent bonding effect could suppress the formation of aggregated particles during heat treatment.Melamine was further introduced as both a cost-effective nitrogen resource and blocking agent retarding the migration of metal atoms.The optimized catalyst has proven to have abundant atomically dispersed Fe-N4 active sites with enhanced ORR catalytic performance in acid condition.This method has provided new feasible ideas for the synthesis of SACs.