Abstract
All composite membranes have indeed lower methanol permeability and higher proton conductivity than pure DE2020 membrane. The composite membranes with Si/Al ratio 25 and 5 wt.% of zeolites (DEZ25-5) having the lowest methanol permeability and the membrane with Si/Al ratio 50 and I wt.% of zeolites (DEZ50-1) having the highest proton conductivity were tested in the DMFC for several days. The DEZ25-5 has the best performance; namely high power density and stable performance in time