Crossover Rate of Methanol and Ethanol through Proton Exchange Membrane

초록

Small organic molecules (i.e. methanol, ethanol) could be used as fuels of energy conversion device from chemical energy to electrical energy. However, those fuels are diffused through membranes due to the small size of fuels. Furthermore, fuel crossover through PEM (proton exchange membrane) causes not only the loss of fuels but also the loss of cathode performance. Therefore, the crossover rate of fuel should need to be investigated by electrochemical method quantitatively. In our work, we are investigating the crossover rate of fuel by using the electrochemical stripping method with various diffusion times. Fig.1 shows the schematic of experimental apparatus; (a) is H-type electrochemical cell, (b) is the enlargement of PEM with two electroless deposited Pt electrode [1]. The quantitative analysis of methanol diffused through polymer membrane was performed by using stripping process of CO known as intermediate species in methanol oxidation [2]. Fig.2 shows the stripping voltammogram of Pt for 0.1M methanol diffused through PEM in 0.5M H2SO4. We also investigated the ethanol oxidation by using stripping voltammetry and the comparison of crossover rate between methanol and ethanol.