Adsorption configuration control on Pt-Bi2O3 for the oriented conversion of glycerol to glyceric acid via terminal hydroxyl oxidation.

Abstract

Glycerol, a byproduct of biodiesel production, can be efficiently converted into valuable chemicals through electrocatalytic reaction. In this study, platinum (Pt) nanocrystals decorated on bismuth oxide (Bi₂O₃) nanosheets (PtBi DONS) with an optimal Pt:Bi ratio of 1:1 were successfully synthesized using a galvanic replacement method. Pt₁Bi₁ DONS exhibit remarkable electrocatalytic performance for glycerol electrooxidation, achieving an excellent catalytic activity (current of 0.82 A mg_Pt^-1 at 0.67 V vs. reversible hydrogen electrode (RHE)) and an exceptional selectivity of 96.6% for C₃ products, particularly glyceric acid. The superior performance stems from two key factors: (1) electron transfer from Bi₂O₃ to Pt creates electron-rich Pt sites that suppress C-C bond cleavage and (2) Bi₂O₃ facilitates favorable glycerol adsorption configurations through multiple hydroxyl group interactions. Mechanistic studies using operando spectroscopy and electrochemical impedance spectroscopy revealed that the synergistic effect between Pt and Bi₂O₃ promotes rapid charge transfer and stable intermediate formation. Moreover, PtBi DONS showed excellent versatility in oxidizing other polyols compared with monoalcohols.