High-Dimensional Nb2O5 with NbO6 Octahedra for Efficient Electrocatalytic Upgrading of Methanol to Formate.

Facilitating the selective electrochemical oxidation of methanol into value-added formate is essential for electrochemical refining. Here we propose a high-dimensional Nb₂O₅ on Ni foam (Nb₂O₅-HD@NF) composite as anode for methanol oxidation reaction (MOR) for efficient production of formate. In an electrolyte containing 3 M methanol aqueous solution, the Nb₂O₅-HD@NF anode requires only 240 mV overpotential to deliver an industrial-level current density of 100 mA cm^-2 with a formate Faraday efficiency of 100%. In situ Raman and electrochemical kinetic analyses reveal that the origin of the excellent activity in 3 M methanol electrolyte can be ascribed to the NbO₆ octahedra as active sites and the Lewis acid sites on the surface of Nb₂O₅-HD. This work may pave a way for the design of non-noble metal electrocatalysts with surface acidity engineering for the effective electrocatalytic upgrading of biomass molecules.