In situ XAFS and HAXPES analysis and theoretical study of cobalt polypyrrole incorporated on carbon (CoPPyC) oxygen reduction reaction catalysts for anion-exchange membrane fuel cells

Asazawa, Koichiro*; Kishi, Hirofumi*; Tanaka, Hirohisa*; Matsumura, Daiju   ; Tamura, Kazuhisa   ; Nishihata, Yasuo; Saputro, A. G.*; Nakanishi, Hiroshi*; Kasai, Hideaki*; Artyushkova, K.*; Atanassov, P.*

Non-noble metal electrocatalysts not only are a solution to limited resources but also achieve higher efficiency for fuel cells, especially in alkaline media such as alkaline membrane fuel cells. Co-polypyrrole-based electrocatalysts provide high oxygen reduction reaction (ORR) reactivity, but the active sites and reaction mechanism have yet to be elucidated fully. In this study, ex situ and in situ synchrotron characterization and theoretical study have been combined to evaluate the ORR mechanism on two possible active sites consisting of Co coordinated with pyrrolic nitrogen and Co coordinated with pyridinic nitrogen.