Résumé
The electrocatalytic oxidation of organic molecules is emerging as an effective method for low-energy input hydrogen production in membrane reactors. Glycerol is a promising hydrogen source due to a given low thermodynamic barrier of its electrooxidation in alkaline medium, the possibility to co-generate valuable compounds and low overall cost. Bimetallic electrocatalysts are interesting because of the resulting electronic interactions. Coupled with gold, silver leads to the decrease of the onset potential of glycerol electrooxidation and to the rapid removal of oxidation products, which allows improving kinetics and selectivity[1].This work describes our effort to design stable and three-dimensional metallic materials with porous, alloy, core-shell structures using different methods (electrodeposition, galvanic replacement, gamma irradiation) for selective glycerol oxidation in alkaline media.The results provide new insigths: (i) implementing a new class of free-standing electrode materials with direct and stable attachment of Ag-Au metal particles on gas diffusion electrodes (GDE) avoiding the need to prepare a catalytic ink, (ii) revealing their morphology and composition depending on the method implemented, (ii) demonstrating competitive electrocatalytic glycerol oxidation performance with an onset potential of less than 0.7 V vs. RHE and current densities between 100 and 290 mA cm-2, (iv) attesting to the selective electrooxidation of glycerol into only two very interesting products, formate (66%) and glycolate (32%) [2].(1) N. Tuleushova, Y. Holade, D. Cornu, S. Tingry, Electrochemical Science Advances, 2022, e2100174.(2) R. Boukil, N. Tuleushova, D. Cot, B. Rebiere, V. Flaud, V. Bonniol, J. Cambedouzou, S. Tingry, D. Cornu, Y. Holade, J. Mater. Chem. A., 2020, 8, 8848.