Pentagon-Rich Caged Carbon Catalyst for the Oxygen Reduction Reaction in Acidic Electrolytes

The interaction between electron spin and oxygen molecules in non-platinum catalysts, particularly carbon catalysts, significantly influences the catalytic performance of the oxygen reduction reaction (ORR). A promising approach to developing high-performance catalysts involves introducing five-membered ring structures with spin into graphitic carbons. In this study, we present the successful synthesis of cage-like cubic carbon catalysts enriched with pentagon structures using pentagon ring-containing C₆₀ and a NaCl template. The number of pentagons contained in the structure was increased by doping with nitrogen and annealing, and the number of electron spins also increased, thereby improving catalytic activity. The prepared catalyst exhibits remarkable activity in ORR under acidic electrolytes. Furthermore, we elucidate the correlation between the pentagon structure, the number of spin, and catalytic activity, demonstrating that enhanced activity is contingent upon the presence of spin. Density functional theory (DFT) calculations support the role of spin in improving activity. The concept of spin and the introduction of pentagon structures provide new design principles for carbon catalysts.