Coupling Ti-assisted secondary-hydroxyl activation with H-regulated radical overoxidation control on WO3 photoanodes for highly selective glycerol to dihydroxyacetone conversion

A TiCl 3 -based route enables H insertion and dispersed Ti sites on WO 3 photoanode. • Dispersed Ti sites favor secondary-hydroxyl activation and DHA formation. • H insertion suppresses free •OH species and mitigates DHA overoxidation. • (H,Ti)/WO 3 achieves 71.9% DHA selectivity and 264.5 mmol m −2 h −1 productivity. Selective photoelectrochemical oxidation of glycerol to dihydroxyacetone (DHA) offers a compelling strategy for integrating solar energy conversion with biomass valorization. However, efficient DHA accumulation remains challenging because two key issues are often underemphasized: the atomic level control of glycerol adsorption geometry for secondary-hydroxyl oxidation, and the suppression of radical mediated overoxidation of the formed DHA. Herein, we report a H, Ti-dual-modified WO 3 photoanode (H,Ti)/WO 3 that enables highly selective glycerol oxidation to DHA via cooperative interfacial pathway regulation. The (H,Ti)/WO 3 photoanode achieves a DHA selectivity of 71.9%—a sharp rise from 35.7% for WO 3 , and a DHA production rate of 264.5 mmol m −2 h −1 , roughly 5 times that of the unmodified counterpart. Mechanistically, highly dispersed Ti sites enhance adsorption of the secondary hydroxyl group of glycerol, directing the pathway toward DHA via two‑electron transfer. H‑insertion, in contrast, shifting hydroxyl chemistry away from free •OH mediated deep oxidation toward more surface-bound hydroxyl species and thereby suppressing DHA overoxidation. With this dual-pronged strategy, our work provides new insights into the selective formation and stable accumulation of DHA in biomass photoelectrochemical systems. Download: Download high-res image (146KB) Download: Download full-size image