Incorporation of Cu/Ni in Ordered Mesoporous Co-Based Spinels to Facilitate Oxygen Evolution and Reduction Reactions in Alkaline Media and Aprotic Li-O2 Batteries

Ordered mesoporous CuNiCo oxides were prepared via nanocasting with varied Cu/Ni ratio to establish its impact on the electrochemical performance of the catalysts. Physicochemical properties were determined along with the electrocatalytic activities toward oxygen evolution/reduction reactions (OER/ORR). Combining Cu, Ni, and Co allowed creating active and stable bifunctional electrocatalysts. CuNiCo oxide (Cu/Ni approximate to 1 : 4) exhibited the highest current density of 411 mA cm(-2) at 1.7 V vs. reversible hydrogen electrode (RHE) and required the lowest overpotential of 312 mV to reach 10 mA cm(-2) in 1 m KOH after 200 cyclic voltammograms. OER measurements were also conducted in the purified 1 m KOH, where CuNiCo oxide (Cu/Ni approximate to 1 : 4) also outperformed NiCo oxide and showed excellent chemical and catalytic stability. For ORR, Cu/Ni incorporation provided higher current density, better kinetics, and facilitated the 4e(-) pathway of the oxygen reduction reaction. The tests in Li-O-2 cells highlighted that CuNiCo oxide can effectively promote ORR and OER at a lower overpotential.

Automated summary

Ordered mesoporous CuNiCo oxides prepared by nanocasting demonstrate excellent electrocatalytic performance for oxygen reduction and oxygen evolution reactions, with the optimal Cu/Ni ratio being 1:4.