Physically mixed graphene aerogel:carbon black (GA:CB)-supported Pt or hydrothermally synthesized GA-Pt/CB hybrid electrocatalysts for PEM fuel cells

Graphene aerogels (GAs), having the superior properties of graphene and aerogel structures, are promising support materials for Pt nanoparticles to be used as electrocatalysts for PEM fuel cells. In this study, two routes were followed to synthesize GA-based electrocatalysts. In the first route, after GA synthesis it was physically mixed with carbon black (CB) by changing the mass ratios from 0% to 100% with 25% increments and then decorated with Pt nanoparticles via microwave irradiation, resulting in Pt/GA:CB electrocatalysts. In the second route, firstly, Pt/CB electrocatalyst was synthesized and then GA was hydrothermally added to the Pt/ CB by changing the mass ratios of GA:Pt/CB from 0% to 100% with 25% increments, resulting in GA-Pt/CB electrocatalysts. The electrocatalysts synthesized were physically characterized (ICP-OES, XRD, Raman, SEM, TEM, surface area, and contact angle) and then in situ PEM fuel cell tests were performed. Following different synthesis routes resulted in different physical properties. The hydrothermally synthesized electrocatalysts gave a better PEM fuel cell performance when compared to the physically mixed ones.