Construction of hierarchical NiCu-based bimetallic electrocatalysts for promoting the electrooxidation of biomass derivatives†
Abstract
Replacing the oxygen evolution reaction (OER) which is limited by intrinsic sluggish kinetics with the more thermodynamically favorable 5-hydroxymethylfurfural electrooxidation reaction (HMFEOR) to couple with the hydrogen evolution reaction (HER) is of significant importance to produce sustainable value-added products and green hydrogen. Herein, we report a Ni–Cu-based hierarchical electrocatalyst, fabricated via a facile one-pot sequential deposition hydrothermal process. For the HMFEOR, a high current density of 400 mA cm−2 is achieved with a low overpotential of 222 mV. The catalyst exhibits a high faradaic efficiency of over 98% for FDCA and excellent long-term stability. The enhanced HMFEOR activity and the good cycling durability of the catalyst are ascribed to the hierarchical heterogeneous structure. The crystalline Cu2O doped amorphous Ni(OH)2 heterogeneous structure provides increased active sites for the HMFEOR without sacrificing conductivity, and the layered hierarchical structure provides high activities for both the aldehyde group and alcohol group.