Energy-saving H2 Generation Coupled with Oxidative Alcohol Refining over Bimetallic Phosphide Ni2 P-CoP Junction Bifunctional Electrocatalysts

ChemSusChem. 2021 Dec 17;14(24):5450-5459. doi: 10.1002/cssc.202101841. Epub 2021 Oct 28.

Abstract

The realization of large-scale H2 production from electrocatalytic water splitting is severely impeded by the kinetically sluggish and economically less viable anodic oxygen evolution reaction. Here, an efficient strategy was established for the concurrent H2 production and oxidative alcohols refining into value-added formate by utilizing self-supported Ni2 P-CoP bifunctional electrocatalysts. Benefiting from high intrinsic activity, abundant active sites, and synergistic promoting effects of bimetallic phosphides, the constructed two-electrode electrolyzer required a cell voltage of around 1.3 V to achieve 10 mA cm-2 , which is more than 200 mV lower than that of pure water splitting. Moreover, simultaneous productions of H2 with near-unity conversion efficiency and formate at high faradaic efficiencies of 99.8 and 89.6 % oxidatively produced from methanol and glycerol, respectively, were achieved with excellent durability. This work presents a general and economic approach toward the fabrication of cost-effective electrocatalysts for energy-efficient and profitable large-scale renewable energy integration.

Keywords: alcohol oxidation reaction; electrochemistry; formate; hydrogen; metal phosphide.