Investigation of the electrochemical behaviour in DMFCs of chabazite and clinoptilolite-based composite membranes

Composite membranes based on recast Nafion with the inclusion of chabazite and clinoptilolite as fillers were used to increase the operation temperature of direct methanol fuel cells (DMFCs). Membranes containing different amounts (3 and 6 vol%) of these zeolites were prepared. The electrochemical behaviour of the composite membranes was investigated at different temperatures (from 90 up to 140 oC). Similar performances (around 350-370mWcm-2 under oxygen feed, 200-210mWcm-2 under air feed, at 140 oC) were recorded for the cells based on the composite membranes with 3 and 6 vol% of zeolite filler. Cell resistance measurements showed an improvement of the water retention properties at high temperature for the composite membranes compared to bare Nafion