in situ 軟X線吸収分光法を用いたイオノマー/電極界面挙動解析

Abstract

The Interface Structure between ionomer and electrode such as specific absorption of sulfonic acid of the ionomer strongly influence ORR activity. The interface structure is significantly sensitive to previous-treatments and water circumstance. We have developed the novel method to measure electronic structure of sulfonic acid of the ionomer by in situ soft X-ray absorption spectroscopy. The sulfur K-edge XANES clearly indicated the sulfonic acid of Nafion has two peaks corresponding the specific absorption species and the free species. By changing the incident angle of X-ray, polarization dependent was unambiguously confirmed which indicates specific absorption species of sulfonic acid is located and strong interaction in the near-interface region than bulk zone.