Nanoscale Pt over MoTe <sub>2</sub> flower with synergistic anti-poisoning ability for methanol electrolysis
Fangfang Ren, Yang Zhou, Yajing Xie, Fuling Yang, Ligang Feng
Abstract
Methanol-assisted water electrolysis presents a promising yet challenging technique for electrochemical hydrogen production as limited by the easy poisoning issue of Pt active sites. In this study, we successfully synthesized an efficient bifunctional catalyst composed of 3D flower-like MoTe<sub>2</sub> embedded nitrogen-doped carbon nanospheres, assembled by nanosheets, to support Pt nanoparticles (Pt-MoTe<sub>2</sub>/NC) for methanol-assisted water electrolysis. This innovative Pt-MoTe<sub>2</sub>/NC catalyst demonstrated superior catalytic performance targeting both hydrogen evolution reaction (HER) and methanol oxidation reaction (MOR) due to the strong metal-support interaction and the promotional effect of oxophilic molybdenum telluride. In situ infrared spectroscopy and CO stripping measurements revealed their excellent anti-poisoning ability. In particular, the onset potential of CO oxidation decreased by 130 mV relative to the standard Pt/C electrode. Theoretical calculations indicated the proper H* adsorption energy for HER and weakened CO adsorption energy for MOR in the optimized electronic structure. Therefore, the Pt-MoTe<sub>2</sub>/NC electrode achieved the highest forward peak current density (76.6 mA cm<sup>-2</sup>) for MOR, approximately 2.8-fold that of the commercial Pt/C, and only 34 mV was needed to deliver 10 mA cm<sup>-2</sup> for HER in acidic electrolyte. When employed as the bifunctional electrode in methanol electrolysis, Pt-MoTe<sub>2</sub>/NC enabled efficient hydrogen generation with good stability, requiring merely 0.65 V to achieve 10 mA cm<sup>-2</sup>, approximately 1090 mV less than traditional water electrolysis. This work presents an anti-poisoning catalyst in energy-saving hydrogen production from methanol electrolysis.