Strengthening the oxygen reduction stability and activity of single iron active sites via a simultaneously electronic regulation and structure design strategy

Single-atom iron-nitrogen-carbon materials have demonstrated remarkable potential in catalyzing the oxygen reduction reaction (ORR). In this study, a novel approach is proposed for regulating the microenvironment of single iron sites through the coupling of neighboring Zn with an open-mesoporous carbon plane. This structural arrangement effectively modulates the density of states and d-band center of Fe atoms, resulting in moderate adsorption and desorption of oxygen intermediates and thereby reducing the energy barrier of the ORR. Moreover, the open-mesoporous structure ensures the accessibility of the active sites and facilitates the mass transfer of reactants, intermediates, and products during the ORR. Consequently, the synthesized M-Fe-ZnNC catalyst exhibits enhanced ORR performance and excellent stability. This study serves to inspire the exploration of high-performance non-precious metal catalysts for the ORR, leveraging simultaneous electronic regulation and structure design.