Co‐N as a Promoter towards Modulation Surface Chemistry of PtCo Alloy on 2D Thin Layer Hierarchical Porous Nitrogen‐Carbon for the Efficient Oxygen Reduction Reaction

Abstract To clarify the mechanism of active site conversion and utilization of the Pt−M alloy complexed with nitrogen‐doped carbon (NC) catalysts (Pt−M/NC) for oxygen reduction reaction (ORR), we synthesized the two‐dimensions thin‐layer hierarchical porous nitrogen‐carbon for supporting PtCo nanoparticles (2D PtCo/TNC) and applied to alkaline ORR. The self‐assembled thin layer of carbon nitride (TL‐C 3 N 4 ) was thermally fused with commercial carbon black (C) to form a 2D‐TNC, which can conduct the optimal mass transfer. Therewith, PtCo nanoparticles were anchored on this carrier through a thermal injection strategy, promoting the formation of Co−N and achieving low Pt loading (2 wt%). As a promoter, the Co−N favours the lattice distortion of PtCo alloys and facilitates the in‐situ adsorption‐diffusion process of oxygen‐containing species. Thus, the obtained catalyst demonstrates an excellent ORR activity in alkaline electrolytes, with a half‐wave potential (E 1/2 ) of 0.885 V and electrochemical active surface area (ECSA) of 111 m 2 /g, lower Tafel slope of 66 mV/dec.