Comparison of methanol, ethanol and iso-propanol oxidation on Pt and Pd electrodes in alkaline media studied by HPLC

The oxidation of methanol, ethanol and iso-propanol and their respective product formation on platinum and palladium electrodes in alkaline solution are studied by voltammetry combined with high performance liquid chromatography. The oxidation products observed at platinum are formaldehyde and formate for methanol, acetaldehyde and acetate for ethanol and acetone for iso-propanol oxidation. On palladium, the same products (except formaldehyde) are detected. Palladium appears to be a better catalyst for the selective oxidation of the alcohol group in alkaline media, but as soon as poisoning by adsorbed carbon monoxide plays a significant role, such as in methanol oxidation, platinum is the preferred catalyst.

Research highlights
► HPLC can be combined with voltammetry to obtain liquid reaction products.
► Pd is a selective catalyst for alcohol oxidation to corresponding acid in base media.
► Pt is a good catalyst for adsorbed CO also in alkaline media.
► Acetone is the only liquid product of 2-Propanol oxidation on Pt and Pd electrodes.