Methanol permeation through proton exchange membranes of direct methanol fuel cells.

摘要

Methanol permeation through proton exchange membranes is one of the major constraints inhibiting large scale commercialization of direct methanol fuel cell (DMFC). Potentiometric technique was used to determine methanol crossover flux and permeability of prepared SPEEK/TPA/MCM-41 and SPEEK/TPA/Y-zeolite composite membranes.; SPEEK/TPA/MCM-41 composite membranes with inorganic loadings (TPA/MCM-41) of 10wt %-30wt % have permeability values of 0.57 x 10-8 cm 2 s-1--3.51 x 10-8 cm 2 s-1. While SPEEK/TPA/Y-zeolite composite membranes with inorganic loadings (TPA/Y-zeolite) of 10wt % -30 wt % have permeability values of 1.71 x 10-8 cm2 s-1--4.29 x 10-8 cm 2 s-1. These values are low compared to that of pure SPEEK 1.6 membranes; 4.41 x 10-8 cm2s -1. But when 40wt % of TPA/Y-zeolite loading was used higher permeability value of 7.04 x 10-8 cm2s -1 was obtained. Better reduction in methanol permeation was observed with lower loadings of the inorganic material (TPA/MCM-41 or Y-zeolite) than with higher loadings. These composite membranes have good potential for use in the direct methanol fuel cell (DMFC) due to their low methanol permeability.