Electrochemical and in situ IR characterization of PtRu catalysts for complete oxidation of ethylene glycol and glycerol

Unsupported nanostructured PtRu electrocatalysts were synthesized using a spray pyrolysis process with varying atomic compositions. A ruthenium rich and platinum rich PtRu were compared to supported E-Tek PtRu on Vulcan XC-72 at a pH range from 5 to 8 for the oxidation of ethylene glycol and glycerol. Oxalic acid is also evaluated as a fuel because it is a terminal oxidation product of glycerol oxidation that enzymes cannot successfully oxidize electrochemically. The nanostructured catalysts were evaluated by SEM and exhibited a sponge-like morphology that helped to increase the metal utilization despite its low surface area. In situ FTIR spectroscopy was used to probe the reaction to determine if complete oxidation occurred by monitoring the production of CO2. The nanostructured catalyst successfully oxidized each fuel (oxalic acid, ethylene glycol, glycerol) to CO2 with no indication of CO formation. This presents an interesting opportunity to combine enzymatic catalysts with metallic Pt-based catalysts for oxidation of more complex fuels.

► PtRu nanostructured catalysts for oxidation of alcohols. ► Oxidation in neutral media and room temperature. ► Oxidation study ranging from pH 5 to 8 in phosphate buffered solution. ► Evolution of CO2 from oxalic acid, ethylene glycol, and glycerol.