Selective Electroreduction of Glycerol to 1,2-Propanediol on a Mixed Carbon-Black Activated Carbon Electrode and a Mixed Carbon Black-Diamond Electrode

1,2-propanediol was selectively produced by electroreduction of glycerol in a two-compartment reactor. Two new kinds of cathode electrodes were evaluated: (i) mixed carbon black-activated carbon electrodes and (ii) mixed carbon black-diamond electrodes. These electrodes were compared with a conventional platinum electrode. With a reaction temperature of 80 °C, an electric current of 2.0 A, and ambient pressure, the mixed carbon black-activated carbon electrode demonstrated excellent performance and successfully reduced glycerol to 1,2-propanediol with a high selectivity of 86% and 74% glycerol conversion. The selectivity of 1,2-propanediol on the mixed carbon black-diamond electrode and the platinum electrode was 68% and 61%, respectively, with 88% glycerol conversion on the mixed carbon black-diamond electrode and 67% glycerol conversion on the platinum electrode. The authors propose a possible reaction mechanism for the formation of 1,2-PDO.