Nickel-Doped Copper Oxide Nanorods for Efficient Biomass Electro-Oxidation

Cu-based catalysts are regarded as promising materials for the electro-oxidation of biomass. However, developing effective strategies to improve the intrinsic activity of Cu-based catalysts is still challenging and rarely reported. Herein, we synthesized a nickel-doped copper oxide catalyst (Ni-CuO_x) for 5-hydroxymethylfurfural (HMF) electro-oxidation to 2,5-furandicarboxylic acid (FDCA). The Ni-CuO_x exhibited a large current density of 199.7 mA cm^-2 at 1.4 V, which is 2.8-fold higher than that of pure CuO_x, and exceeds most of the reported Cu-based catalysts. Moreover, the Ni-CuO_x also showed high FDCA yield (90.1%) and Faradaic efficiency (98.5%). Physical characterizations and electrochemical analyses demonstrated that Ni doping optimizes the electronic structure of Cu sites, and promoting the adsorption of HMF, contributing to enhanced electrocatalytic activity. This work provides insights into the rational design of copper-based catalysts for biomass electro-oxidation.