Polyoxymethylenedimethylether (CH3O(CH2O)nCH3) oxidation on Pt and Pt/Ru supported catalysts

Polyoxymethylenedimethylethers CH3O(CH2O)nCH3 with n varying from 1 to 4 are studied for a possible application as fuels in PEMFC. Cyclic voltammetry is performed at Pt, Pt/Ru(50/50), Pt/Ru(80/20) electrodes in acidic medium to evaluate their electroactivity. Electrical performance of the fuels are evaluated in a 5 cm2 direct fuel cell for different temperatures and pressures with Pt and Pt/Ru(50/50) catalysts at the anode and Pt at the cathode. The determination of the reaction products is performed in a 25 cm2 direct fuel cell under working conditions at constant current for 3 h. Preliminary results are very promising regarding achieved power densities. Results pointed out the important role of hydrolysis of these compounds into methanol and formaldehyde in electroreactivity. It is probable that the cell performances are due to the oxidation of the products coming from hydrolysis rather than to direct oxidation of the polyoxymethylenedimethylethers. Polyoxymethylenedimethylethers appear to be attractive candidates as alternative to methanol, which moreover is a toxic (neurotoxin) molecule.