A Review of Molecular-Level Mechanism of Membrane Degradation in the Polymer Electrolyte Fuel Cell

Abstract

Chemical degradation of perfluorosulfonic acid (PFSA) membrane is one of the most serious problems for stable and long-term operations of the polymer electrolyte fuel cell (PEFC). The chemical degradation is caused by the chemical reaction between the PFSA membrane and chemical species such as free radicals. Although chemical degradation of the PFSA membrane has been studied by various experimental techniques, the mechanism of chemical degradation relies much on speculations from <em>ex-situ</em> observations. Recent activities applying theoretical methods such as density functional theory, <em>in</em><em> situ</em> experimental observation, and mechanistic study by using simplified model compound systems have led to gradual clarification of the atomistic details of the chemical degradation mechanism. In this review paper, we summarize recent reports on the chemical degradation mechanism of the PFSA membrane from an atomistic point of view.

Keywords

• polymer electrolyte fuel cell
• perfluorosulfonic acid membrane
• chemical degradation
• molecular level analysis