Electrochimica Acta, Vol.108, 350-355, 2013
Hydrolyzed polyoxymethylenedimethylethers as liquid fuels for direct oxidation fuel cells
Polyoxymethylenedimethylether (POMM) fuels were investigated as alternatives to methanol for direct oxidation fuel cells (DOFCs) due to their advantageous properties, including negligible toxicity, low vapor pressure (comparable to that of pure water) and their feasibility for mass production in the future. As typical examples of the general class CH3-O-(CH2-O)(n)-CH3 (n=1-8) molecules (abbreviated as POMMn), POMM2 and POMM3 were studied in detail, specifically regarding the hydrolysis kinetics and anodic oxidation on Pt-Ru alloys over a wide range of operating temperatures. It was revealed that they were stable in pure water but formed methanol and formaldehyde easily through a first order hydrolysis reaction in the presence of acidic catalysts. A facile hydrolysis reaction was demonstrated in a convertor packed with particles of the acidic ion-exchange resin Amberlite, in comparison with that in HClO4 solution. The reaction rate increased with increasing n-value but it is expected that adequate reactivity will be retained in a similar range within the family. It was revealed that the fully hydrolyzed POMMn showed anodic oxidation performance on PtRu catalysts several times higher than that of methanol, considering an equivalent electron-discharge capacity, over the temperature range from 30 degrees C to 90 degrees C. (C) 2013 Elsevier Ltd. All rights reserved.
Keywords:Polyoxymethylenedimethylether;Hydrolysis;Platinum-ruthenium electrocatalyst;Liquid fuel;Direct oxidation fuel cell