Orthogonal Design of Competing Deprotonation Process in Cation-Mediated Ni(OH)2 for Achieving Industrial Level Biomass Electrooxidation.

The electrooxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) has attracted great attention in biomass value-added conversion. However, the central challenge for achieving industrial-level scalable biomass upgrading is that the catalysts' inherent preference for activating O─H bond in the competitive oxygen evolution reaction (OER) over the strong C─H bond in organic molecules. Herein, we designed a Cu-substituted Ni(OH)2 catalyst with orthogonal activity by precise valence engineering, selectively activating the aldehyde C─H in HMF oxidation while remaining inert toward the O─H cleavage in OER. Mechanistic studies and in situ characterizations confirm that the incorporation of Cu creates a unique local environment that fine-tunes the deprotonation kinetics in two competing reactions, thereby improving selectivity and activity. This specific orthogonal design delivers outstanding performance, achieving an industrial-scale current density of 1 A cm-2 at 1.55 V vs. RHE with a high Faraday efficiency for FDCA of 99.5%, which is comparable to the best catalysts reported to date. More importantly, the catalyst is continuously stable over 15 cycles. This work provides a new strategy for designing advanced electrocatalysts to achieve selective biomass conversion under industrial-scale conditions.