Insights on the Roles of Nitrogen Configuration in Enhancing the Performance of Electrocatalytic Methanol Oxidation over Pt Nanoparticles

Abstract

AbstractStabilization of the Pt in N‐doped carbon materials is an effective method to improve the performance of electrocatalytic methanol oxidation reaction (MOR). Nevertheless, the roles of different N configurations (pyridinic N, pyrrolic N, and graphitic N) toward the electrochemical performance of Pt‐based catalysts remain unclear. Herein, Density Functional Theory calculations are adopted to elucidate the synergistic promotion of MOR by different N‐configurations with Pt nanoparticles (NPs). Guided by the theoretical study, a series of MOR electrocatalysts with different ratios of pyridinic N and pyrrolic N (denoted as Pt/N‐CNT‐X (500, 600, 700, 800, and 900)) are designed and synthesized. Surprisingly, the electrocatalytic activity of Pt/N‐CNT‐600 with a suitable ratio of pyrrolic‐N and pyridinic‐N for MOR reaches 2394.7 mA mg−1Pt and 5515.8 mA mg−1Pt in acidic and alkaline media, respectively, which are superior to the Pt/CNTs, commercial Pt/C, and the ever‐reported Pt‐based electrocatalysts. The strong metal‐support interaction induced by the N‐doping is the crucial reason for the superior electrocatalytic performance. More importantly, the ability of pyrrolic‐N and pyridinic‐N in promoting the adsorption and oxidation of CH3OH and the oxidation of CO* is substantiated for the first time in methanol oxidation. This work provides new insights on the design of efficient electrocatalysts for MOR.