Engineering atomically dispersed dual Pt-Ni sites on nitrogen-doped carbon with spherical core-shell structure for enhanced oxygen reduction activity towards microbial fuel cell

Inspired by the development of efficient, durable electrocatalytic functional materials to address the issues kinetic retardation and mass transport to enhance oxygen reduction reaction (ORR), one strategy is proposed core-shell structural nitrogen-doped carbon with atomically dispersed binary platinum-nickel (Pt-Ni) atoms (N-C@Pt-Ni/N-C) with controlled bimetallic sites and adjusted electronic coordination environment. Practical application of experimental and simulated theoretical calculation results show the coordination microenvironment optimization for active site can promote the charge rearrangement of Pt-Ni sites, thus regulating the free energy of the reaction intermediates of oxygen-containing species. The N-C@Pt-Ni/N-C reveals astounding catalytic capacity during ORR, leading to a large power density (1472.6 +/- 50.6 mW m(-2)) and long-term reliability (OCP by the current loss with 0.1 mA) in the actual microbial fuel cells. This work not only reveals controllable preparation of functional materials with binary isolated atomic dispersion, but also presents more perspective of electronic structure optimal performance enhancement relationship at the atomic-sized active sites.