Strong synergy between physical and chemical properties: Insight into optimization of atomically dispersed oxygen reduction catalysts

Atomically dispersed catalysts exhibit significant influence on facilitating the sluggish oxygen reduction reaction (ORR) kinetics with high atom economy, owing to remarkable attributes including nearly 100% atomic utilization and exceptional catalytic functionality. Furthermore, accurately controlling atomic physical properties including spin, charge, orbital, and lattice degrees of atomically dispersed catalysts can realize the optimized chemical properties including maximum atom utilization efficiency, homogenous active centers, and satisfactory catalytic performance, but remains elusive. Here, through physical and chemical insight, we review and systematically summarize the strategies to optimize atomically dispersed ORR catalysts including adjusting the atomic coordination environment, adjacent electronic orbital and site density, and the choice of dual-atom sites. Then the emphasis is on the fundamental understanding of the correlation between the physical property and the catalytic behavior for atomically dispersed catalysts. Finally, an overview of the existing challenges and prospects to illustrate the current obstacles and potential opportunities for the advancement of atomically dispersed catalysts in the realm of electrocatalytic reactions is offered.