Curved interfaces-enhanced oxygen reduction reaction by PtCo alloys anchored MOF-derived carbon

Carbon supports employed in the oxygen reduction reaction (ORR) catalysts frequently exhibit crumpled, curled, or other curved morphological features. The local microenvironment generated by such curved interfaces and its impact on the electronic structure of active sites, as well as reaction kinetics, remain to be studied. Herein, the finite element method was employed to elucidate the evolution of the local catalytic microenvironment during the pyrolysis of ZIF-67 from the perspective of geometric distortion. The results revealed that moderate interfacial curvature can significantly enhance the local electric field strength and promote O₂ enrichment. Guided by the simulation results, MOF-derived carbon with an optimal curved configuration was constructed by controlling the pyrolysis temperature. After etching, metal-ion adsorption, and H₂ reduction, MOF-derived carbon materials loaded with PtCo alloy (PtCo/NCs) were obtained. As expected, the PtCo/NCs-900 sample with a moderately curved interface exhibited outstanding ORR performance, with a half-wave potential of 0.831 V and an activity retention of 91.7% after 50 000 s. Density functional theory calculations demonstrated that the curved interface in PtCo/NCs-900 induces electron redistribution, shifts the d-band center of Pt and optimizes the *OH desorption behavior, thereby lowering the O₂ diffusion barrier, facilitating electron transfer, and ensuring sufficient O₂ supply. As an air-cathode catalyst, the PtCo/NCs-900 sample delivered a peak power density of 159 mW cm^-2 and a specific capacity of 837 mAh g^-1_Zn, demonstrating its potential for practical energy applications.