Enhanced Electrocatalytic Performance for Selective Glycerol Oxidation to Formic Acid at a Multiphase AuCu-Ag/AgBr Interface

Electrochemical glycerol oxidation presents a sustainable and environmentally friendly pathway for formic acid production, addressing the significant carbon emissions and resource dependency associated with conventional industrial processes. However, the development of advanced electrocatalysts with high formic acid selectivity and durability remains challenging due to the polyhydroxy structure and carbon chain complexity of glycerol, which lead to intricate oxidation pathways and a wide variety of products. To tackle this issue, we report a AuCu-Ag/AgBr catalyst with a multiphase interface, referring to the integrated boundaries among AuCu, Ag, and AgBr phases that interact with the liquid electrolyte, for high-rate and high-efficiency glycerol oxidation. Comprehensive characterizations reveal that the multiphase interface may effectively modulate the adsorption configurations of glycerol molecules and enhance charge transfer efficiency. Under ambient conditions, glycerol electro-oxidation at 1.43 V for 8 h yielded a conversion of 38% and a formic acid selectivity of 81%, and recycling tests confirmed its high stability under prolonged electrolysis. This synergistic catalytic effect provides a kinetically favorable pathway for formic acid production, demonstrating the potential of AuCu-Ag/AgBr catalysts in advancing sustainable glycerol valorization.