Activating glycerol deep oxidation via Au–TiOx interfacial synergy in bimetallic nanocatalysts

Abstract

Glycerol, as a renewable fuel with high energy density, has broad application prospects in green energy conversion. However, its electrocatalytic oxidation is limited by the activity and selectivity of catalysts, which severely restricts the efficient release of energy. In this work, we report a facile co-reduction synthesis of bimetallic Au–Ti nanoparticles featuring abundant Au–TiO_x interfaces, which nearly doubled the mass activity for glycerol electrooxidation from 1.420 A mg_Au⁻¹ to 2.717 A mg_Au⁻¹ and presented an impressively high mass activity retention after the stability test. In situ attenuated total reflection surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS) analysis confirms that the Au–Ti alloy shows a deeper oxidation behaviour. Density functional theory (DFT) calculations further reveal that the formation of Au–TiO_x interfaces gives rise to bifunctional synergistic sites, which facilitate the cooperative adsorption of glycerol and hydroxyl species, thereby overcoming the limitations of single-type active sites on Au/C. Meanwhile, CO adsorption further enhances the binding of hydroxyl groups, synergistically promoting deep oxidation of glycerol.