Performance enhancement of oxygen reduction reaction in proton exchange membrane fuel cells using magnetic fields under various cathode design conditions

Abstract

Recent research efforts have focused on applying magnetic fields (MFs) to PEMFC (PEMFC^MF) toward the enhancement of oxygen reduction reaction (ORR)-related performances. This study investigates the relationship between MF-induced spin-aligned oxygen and cathode design parameters, including the carbon-supported platinum weight ratio, ionomer-to-carbon weight ratio, and platinum loading amount. Morphology and electrochemical analyses of Pt/C catalysts are conducted to understand the effects of MFs on the ORR performance. The onset and half-wave potentials of the rotating disk electrode (RDE) with MFs are 28 and 45 mV higher, respectively, than those of the RDE without MFs, owing to the increased active oxygen species with aligned spins. The current increase rate of the PEMFC^MF over the PEMFC is more substantial in the high-voltage region because of the enhanced ORR activity of the catalysts. Additionally, cathode designs of PEMFC^MF are optimized to enhance its performance. The maximum performance increment of the optimized PEMFC^MF compared to that of the PEMFC with a platinum loading amount of 0.5 mg_pt cm⁻² is 12.7 % at 0.7 V. These findings indicate that proper cathode designs can enhance the performance of PEMFC^MF-based energy systems.