Selectivity of Nafion-heteropolyacid nanocomposite membranes containing nanoclay for direct methanol fuel cell applications

In this work cesium hydrogen salt of heteropolyacid (Cs2.5H0.5PW12O40) are incorporated into K10 type of montmorillonite in an effort to improve the selectivity ofnafion membrane. Then, nafion-cesium salt of heteropolyacid proton exchange membrane containing clay was prepared via solution casting method for direct methanol fuel cellapplications. The XRD and SEM analyses were conducted to characterize the nanocomposite membrane structure and filler dispersion into membrane matrices. Ion exchange capacity, water uptake, proton conductivity and methanol permeability of nanocomposite membranes wereinvestigated as physical properties of these membranes. Methanol crossover through polymer electrolyte membranes is a critical issue and causes an important reduction of performance in direct methanol fuel cells. Methanol permeability of casted membranes was measured byrefractive index method. Results show all nanocomposite membranes have lower methanol permeability than the recast Nafion membrane. The other results showed increasing amount cesium salt of heteropolyacid increases water uptake and IEC of the membranes therefore byincreasing amount of caesium hydrogen salts of heteropoly acids in the membrane the proton conductivity on the nanocomposite membranes improved

کلیدواژه ها:

Nafion ، heteropolyacid ، montmorillonite ، nanocomposite membrane ، direct methanol fuel cell