Hydrated Tripodal Polydentate Terpyridine Cobalt Complex-Based Metal–Organic Gel as a Bifunctional OER/ORR Electrocatalyst

In the pursuit of a technological breakthrough in zinc-air batteries, it is critical to find economical, durable, and high-performance catalysts for the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) to accelerate the slow reaction kinetics. Herein, a one-pot method was employed to synthesize the polymer within a mixed solvent of CHCl₃ and CH₃OH (v/v = 2:1). The resulting polymer can be well-dispersed in deionized water to form an aqueous metal-organic gel (MOG). Testing has revealed that Co-MOG exhibits dual catalytic properties for both the OER and ORR, a characteristic that is notably rare in original MOG materials. Furthermore, it demonstrates exceptional long-term charge-discharge cycling stability in zinc-air batteries, outperforming several reported Co-based catalysts for the OER and ORR. X-ray absorption spectroscopy and density-functional theory (DFT) calculations indicate that the CoN₃ configuration serves as the catalytically active site of the material. In conclusion, this work supports the application of MOGs as unique bifunctional electrocatalysts for the OER and ORR in metal-air batteries.