Graphene aerogel supported platinum nanoparticles for formic acid electro-oxidation

Abstract

The performance of the direct formic acid fuel cell largely depends on the quality of the electrocatalysts used in the fuel cells. New materials are of great interest in order to improve the activity and stability of the electrocatalyst used in formic acid electro-oxidation for better direct formic acid fuel cell performance. In this study, different support materials including synthesized graphene aerogel (GA), commercial carbon black (C) or their hybrids(GA/C) were used. Platinum (Pt) nanoparticles were decorated on the defect sites of these materials by using microwave irradiation in order to improve the catalytic activity for formic acid electro-oxidation in acidic media. GA/C hybrid supports are synthesized via simple liquid mechanical mixing approach (GA/C(1)) and through hydrothermal process (GA/C(2)). Synthesized catalysts were called Pt/C, Pt/GA and Pt/GA/C(1) and Pt/GA/C(2). The as-prepared catalysts were characterized with SEM, TEM, XRD and ICP-MS. The SEM results show that GA has a 3D macroporous structure. Electrochemical measurements tests showed that either GA or GA/C material is promising support materials for Pt nanoparticles towards formic acid electro-oxidaiton. The electrochemical test results revealed that the support material affect the activity. Synthesized GA supported catalysts gave better activity than synthesized commercial carbon supported catalyst for oxidation of formic acid. Pt/GA and Pt/GA/C(2) catalysts showed higher tolerance against the poisoning effect of CO and direct pathway dominated the electro-oxidation of formic acid.