Nanoscale Morphological Control of PEFC Cathode Electrodes by Introducing Proton Conducting Groups onto Platinum-supported Carbon Black

Abstract

An increase in platinum catalyst utilization in polymer electrolyte fuel cells (PEFCs) is necessary to improve performance and reduce costs. We have previously proposed a novel electrode preparation method, based on the process of grafting a proton-conducting agent onto platinum-supported carbon before the conventional electrode fabrication process. In the present study, platinum-supported carbon grafted with methylsulfonic acid groups (-CH₂SO₃H) and platinum-supported carbon grafted with polyacrylamide tert-butylsulfonic acid groups (Poly-ATBS) were mixed in fabricating the membrane electrode assembly (MEA). The PEFCs' performance of the MEA made from our novel ionomer-grafted platinum-supported carbon material was superior to that of an MEA made using the conventional method using Nafion as an ionomer. The current density at 0.7 V of the MEA using grafted proton-conducting groups on catalyst-supported carbon was 600 mA/cm², which is twice as large as the MEA using nongrafted catalyst-supported carbon.