1D-2D hybridization: Nanoarchitectonics for grain boundary-rich platinum nanowires coupled with MXene nanosheets as efficient methanol oxidation electrocatalysts

Although a direct methanol fuel cell with high energy utilization efficiency and low hazardous emission has broad application prospects in various energy-related fields, the insufficient methanol oxidation activity as well as the short service life of the anode catalysts continue to hinder its large-scale commercialization. Herein, we demonstrate a convenient and robust approach for the controllable synthesis of 1D grain boundary-rich Pt nanowires strongly coupled with ultrathin Ti3C2Tx MXene nanosheets (Pt NWs/MX). Such a unique architectural design endows the heterojunction catalysts with a series of structural merits, including large accessible surface area, stable interconnected Pt networks, numerous grain boundary sites, ameliorative electronic structure, and excellent electron conductivity. Consequently, the optimized Pt NWs/MX catalyst exhibits a unique methanol oxidation performance with a large electrochemically active surface area of 105.5 m2 g-1, a high mass (specific) activity of 1621.5 mA mg-1 (1.6 mA cm-2), as well as superior long-term durability, making it more competitive than conventional Pt nanoparticle/carbon catalysts with the same Pt loading.