Exploring the multifunctionality of Co and Ni selenospinels: unveiling Co3Se4 as an efficient trifunctional electrocatalyst for glycerol, hydrazine, and water oxidation reactions

Abstract

Versatile electrocatalysts that efficiently promote multiple anodic oxidation reactions are highly desirable for hybrid water splitting, an emerging sustainable approach that combines energy-efficient green hydrogen production with biomass valorization. Despite the established prominence of Ni-based materials in small molecule oxidation, the development of superior alternatives remains highly desirable. Herein, we report Co₃Se₄ as an excellent multifunctional electrocatalyst, demonstrating superior catalytic efficiency and durability relative to its Ni analogue for glycerol oxidation (GOR), hydrazine oxidation (HzOR), and oxygen evolution (OER) reactions. A comprehensive study employing experimental and computational routes reveals the factors contributing to the catalytic performance gap between Co and Ni analogues for these reactions. Cobalt selenospinel, despite being drop-cast on an electrochemically inert carbon paper substrate, displayed a current density of 10 mA cm⁻² at 1.13, 0.071, and 1.51 V for the GOR, HzOR, and OER, respectively, highlighting its prevailing performance relative to recently reported catalysts. Substituting the OER with the GOR in the anodic compartment yielded formate with a faradaic efficiency of 76%. Also, integrating the HzOR and GOR with the HER resulted in a reduced energy consumption of 94% and 14%, respectively, further emphasizing the catalytic proficiency of Co₃Se₄ for these alternative anodic reactions.