Furfural Oxidation to Formate Coupled to Hydrogen Production on Zr and In-Doped Co(OH) ₂

The integration of biomass upgrading with hydrogen production in electrocatalytic systems represents a promising strategy for energy conversion. Furfural oxidation, as a route to value-added chemicals, is considered a promising anodic alternative to oxygen evolution in electrocatalysis. Herein, we constructed Zr and In codoped Co(OH)2 (ZrIn-Co(OH)2) nanosheets for efficient furfural oxidation reaction. The introduction of Zr significantly lowers the potential required to form the active phase CoOOH and enhances the catalytic activity, and the addition of In improves the catalyst stability. The optimized ZrIn-Co(OH)2 requires only 1.23 VRHE to deliver a current density of 10 mA cm–2, and shows stable operation for nearly 100 h in alkaline conditions. This catalyst achieves a Faradaic efficiency of 99.25% for the furoic acid (FA) product. More impressively, when coupled with the hydrogen evolution reaction using Pt/ZrIn-Co(OH)2, the H-type cell and membrane electrode assembly flow electrolyzer require only 1.39 and 1.34 V, respectively, to reach 10 mA cm–2. The Faradaic efficiency approaches 100% for both FA at the anode and hydrogen at the cathode, with stability exceeding 100 h. This work highlights the potential of transition-metal-based hydroxide electrocatalysts for upgrading biomass-derived products.