Cu-Ni-Mo-P/C Electrocatalyst for the Co-Generation of Energy and Fine Chemicals from Glycerol Electrooxidation

CuNiMoP/C synthesized using a mixture of sodium hypophosphite and formaldehyde as reducing agents in a single electroless bath has been used as anode side catalysts for the oxidation of glycerol. The copper to nickel ratio in the electroless deposits was 9. The ratio of NaOH/glycerol charged to the anode side of an unstirred divided electrochemical reactor at the beginning of the electro-oxidation was 4. The cathode (platinum) was depolarized with oxygen during each oxidation. The anode and cathode compartments were separated by an anion exchange membrane. Using voltammetry and high pressure liquid chromatography, we show that changing the potential applied at a CuNiMoP/C anode affects both glycerol conversion and product yield/selectivity. The applied anode potentials studied ranged from 0.5 V - 1.3 V (versus Ag/AgCl in satd KCl). The major liquid products obtained were glyceraldehyde, dihydroxyacetone, oxalic acid, lactic acid and tartronic acid at room temperature. Glycerol conversions ranged from 20% to 30% for six to eight hour operations. Electrochemical characterization of the CuNiMoP/C gave a Tafel slope of 130 mV/decade, and an exchange current density of 1.8 mA/cm2. Electrochemical impedance spectroscopy was carried out between 25 0C and 80 0C to study the effect of temperature on impedances, since the higher temperature approximate actual liquid fuel cell conditions. Some preliminary results on the CuNiMoP/C stability while in use, determined from 72 hours uninterrupted use of the electro-catalysts for glycerol electro-oxidation, will also be presented. These results have important implications for portable applications with a direct alkaline glycerol fuel cell. Figure 1