Bi-functional carbon-based catalysts for unitized regenerative fuel cells

Alkaline unitized regenerative fuel cells (URFCs) could well be one of the energy sources in the next future. This technology has the potential to provide power to portable devices, transportation and stationary sectors. The bifunctional oxygen electrode plays a central role in catalytic activity and stability due to its slow kinetics under extremely oxidizing or reducing environments. With the aim to solve the principal catalytic problems at the bifunctional electrocatalysts, carbonaceous materials including carbon nanofibers (CNFs), graphitized mesoporous carbon (gCMK-3) and hydrazine-reduced graphene oxide (H-rGO) were synthesized, characterized and tested toward the oxygen evolution reaction (OER) and the oxygen reduction reaction (ORR) and compared to commercial carbon black (Vulcan), graphite, and glassy carbon (GC). Physicochemical characterization was conducted by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), elemental analysis and Raman spectroscopy, meanwhile rotating ring-disk electrode (RRDE) was employed to determine the electrochemical activity and stability. Main results indicate that CNFs can act as a feasible catalyst for URFC applications. (C) 2020 Elsevier Inc. All rights reserved.