Mesoporous FeCo2O4 nanosheet-supported Pt for oxygen reduction and oxygen evolution reaction bi-functional catalytic performance

Abstract

Abstract The development of new energy storage and conversion pathways has gradually freed people from dependence on oil, and improving conversion efficiency and safety is still the mainstream trend in the development of new energy sources, and electrode catalysts have become crucial in solving these problems. At present, precious metal catalysts have good performance, but the scarcity of resources and the high price limit commercialization. Therefore, it is very important to develop a catalyst for commercialization. In this paper, the Pt nanoparticles were successfully loaded on the mesoporous FeCo2O4 nanosheet catalyst by the sodium borohydride (NaBH4) reduction method. The formation of the Pt-O bond results in covalent coupling between Pt and FeCo2O4. The increase in defect sites also facilitates improved catalytic activity. According to the test results, the ORR process is mainly carried out through the "4-electron reaction" pathway, and the main product is water, and the Tafel slope of Pt-FeCo2O4 (-73 mV dec-1) is smaller than that of Pt/C (-84 mV dec-1) and FeCo2O4 (-76 mV dec-1). The stability of Pt-FeCo2O4 to ORR (After 12 h, only 15.5 % current density loss) is significantly higher than that of commercial Pt/C. Meanwhile, in the OER process, Pt-FeCo2O4 (28.1 mA cm-2) has a higher current density than RuO2 (24.4 mA cm-2) and FeCo2O4 (15.1 mA cm-2). Therefore, Pt-FeCo2O4 can be used as a bifunctional catalyst to accelerate the ORR and OER processes, which has important theoretical research significance and commercial value.