Regulating adsorption selectivity by charge-polarized Auδ−-Cuδ+ site for stable glucose electrooxidation

Abstract

Abstract Electro-reforming of biomass into value-added chemicals offers a sustainable approach for future energy developments. However, noble metal catalysts toward glucose electrooxidation suffer from deactivation, poor selectivity, and limited power density. Here, we present Au δ− -Cu δ+ sites in AuCu alloy that serve as stable and efficient catalyst for selective glucose electrooxidation to potassium gluconate at high current density. AuCu alloy ensures the co-adsorption of OH − on electron-deficient Cu δ+ sites and glucose on electron-rich Au δ− sites, stimulating the formation of oxidative *OH and intermediates. Selective adsorption of OH species on Cu δ+ sites also restrains the Au-OH formation and its subsequent oxidation to AuO x , thereby preventing catalyst deactivation. Especially, for glucose electrooxidation, Au 4 Cu 2 alloy delivers a high selectivity toward potassium gluconate (97.15%), along with a low potential of 0.74 V (versus reversible hydrogen electrode) to achieve industrial current density of 500 mA cm −2 . Furthermore, Au 4 Cu 2 alloy realizes a stable electrolysis with a potassium gluconate productivity of 9.46 mmol cm –2 h –1 and Faraday efficiency of 93.60% in the membrane-free flow electrolyzer.