High-Selectivity Electrocatalytic Oxidation of Glycerol to C3-Glyceraldehyde Coupled to H2O2 Production.

Abstract

Achieving high selectivity of glyceraldehyde (GLD) products remained challenging due to competing C─C bond cleavage and multiple reaction pathways during glycerol electrooxidation. Herein, we designed a PtSb single-atom alloy supported on non-stoichiometric TiO2 (PtSb1/TiOx), which enabled highly efficient and stable GLD production under neutral conditions. The catalyst achieved 87% GLD selectivity with exceptional stability exceeding 120 h. TiOx support suppressed C─C bond cleavage, preserving C3 intermediates, while atomic Sb dispersed in the Pt matrix enhanced GLD selectivity. This further stabilized active sites through Pt─Sb bond formation, which mitigated oxidative deactivation. We integrated PtSb1/TiOx with a Pt-loaded ZnFeWMn medium-entropy oxide for two-electron oxygen reduction, enabling simultaneous production of C3 and H2O2 products. In a membrane-electrode assembly system under neutral conditions, this achieved yields of 0.332 mmol h-1 for GLD and 0.50 mmol h-1 for H2O2. In alkaline media, by controlling H2O2 transport, the system attained 72.9% glycerate selectivity without external bias, representing one of the most efficient bias-free glycerol valorization systems reported. This work pioneered a dual-strategy approach for catalyst engineering to control reaction pathways and system integration for simultaneous high-value chemical production.