Facile Synthesis of Mesoporous Nickel Cobalt Oxide for OER – Insight into Intrinsic Electrocatalytic Activity

The development of novel metal oxide catalysts for electrochemical water splitting has been one of the future challenges in catalysis. We present the development of structured spinel based NiCo2O4 materials using in‐situ hydrothermal synthesis and KIT‐6 as a template. Their electron transfer kinetics in the oxygen evolution reaction (OER) at pH 14 are studied. Structuring of NiCo2O4 via KIT‐6 improves the intrinsic catalyst performance, e. g., a lower overpotential of ∼350 mV and a good long‐term stability could be observed compared to 385 mV and poor stability of commercially available NiCo2O4. Kinetic studies provided insights into structure‐activity relations and the nature of the electrode/electrolyte interface. Interestingly, structuring via KIT‐6 increases not only the electrochemical surface area but also the current density accompanied by superior charge transfer capacity. Structure as key: Templated NiCo2O4 possesses not only higher porosity and surface area but also enhanced intrinsic activity and stability in OER.