Simultaneous Generation of Mesoxalic Acid and Electricity from Glycerol on a Gold Anode Catalyst in Anion-Exchange Membrane Fuel Cells

We report the selective electrocatalytic oxidation of glycerol for the cogeneration of mesoxalic acid and electricity on a gold anode catalyst in anion-exchange membrane fuel cells (AEMFCs). Small Au nanoparticles (3.5 nm) were uniformly deposited onto carbon black with a loading of 40 wt?% through a solution-phase method. An AEMFC with this Au/C anode catalyst, together with an Fe-based cathode catalyst, exhibited a peak power density of 57.9 mW?cm-2 at 80?degrees C. Valuable mesoxalic acid was produced with high selectivity (46?%) from the electro-oxidation of glycerol on Au/C at an operating voltage of 0.3 V, whilst very small amounts of mesoxalic acid (selectivity<3?%) were obtained on a Pt/C anode catalyst in AEMFCs. The product distribution was dependent on the anode overpotential. At 1.2 V versus the standard hydrogen electrode (SHE) in an electrolysis cell, glycolic acid was the major product (selectivity: 65?%) and no mesoxalic acid was observed. Based on the product analysis, we found that Au facilitated deeper-oxidation of glycerol to afford the fully-oxidized C3 mesoxalic acid, rather than C?C cleavage, under a mild potential range (0.40.7 V vs. SHE) that was fortunately within the working voltage range of the fuel cells.