Methanol Cross-over in Direct Methanol Fuel Cells

Abstract

Transport rates of methanol in ionomer membranes exposed to methanol aq. solns. were detd. electrochem. in cells identical to direct methanol fuel cells (DMFCs) and by NMR measurements on the membrane equilibrated with the methanol solns. The electrochem. and NMR results were compared and discussed in the context of temp. and membrane thickness effects on methanol crossover in DMFCs. In addn., results for CO2 emission from the cathode of an operating DMFC were obtained as a function of cell current and methanol concn. in the feed stream, indicating that (a) at low concns. methanol crossover can be lowered by methanol consumption in the anode and (b) at higher concns. methanol is carried across the cell significantly by electroosmosis. [on SciFinder(R)]