Numerical analysis of the effect of charge transfer coefficient (CTC) on bubble evolution of polymer electrolyte membrane (PEM) electrolyzer / Alhassan Salami Tijani, Mohammad Amirul Akmal Mohd Najib and Nabilah Hanum Mustafa

There is a growing concern on the need to enhance the current density of alkaline electrolysis without compromising reduction in efficiency. During the operation of alkaline electrolyzers, a portion of the electrode surface is covered with cloud of bubbles. The bubbles increase ohmic resistance and activation overvoltage of the electrolyte. This study aims to investigate the effect of charge transfer coefficient (CTC) on the voltage characteristics of PEM electrolyzer. Matlab was used to simulate the equations. The simulation result shows that CTC values at the anode electrode range between 0.807 and 1.035. Interestingly, at CTC of 0.5 and 0.2 for anode and cathode, the operating voltage at 1 A/cm2 was observed to be 2.0 V. Also at CTC of 2 and 0.5 for anode and cathode, respectively, there was a significant drop in operating voltage up to 1.62 V with a current density of 1 A/cm2, this accounts for about 27% reduction in operating voltage.