In this work, the effect of copper addition on NiMo coating is evaluated in regard to the hydrogen evolution reaction (HER). NiMo and NiMo–NiCu composites are prepared by a simple coelectrodeposition process. The effect of Cu on deposit characters were tested by varying it in the range of 0.06–0.20 molar ratio. Copper addition promotes the growth of a new crystalline phase: NiCu. Also, the copper addition changed the composite surface. NiMo–NiCu0.12 shows a surface roughness 30 times higher than the NiMo material. NiMo–NiCu materials present higher activity toward HER, larger electroactive area, and higher stability in continuous water electrolysis than NiMo catalysts, as demonstrated by Tafel curves, electrochemical impedance spectroscopy measurements, and polarization tests. The combination of the large electroactive area due to the copper addition, the synergism between Ni–Mo, and the presence of Ni and Mo oxides on the surface results in catalyst with excellent features for HER application.

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Lanthanum‐based perovskites have been gaining attention in recent years as cost‐attractive and efficient catalysts for the oxygen evolution reaction (OER). Showing a simplified LaBO3 stoichiometry (B=transition metal cation), the structure and composition of the perovskites play key roles in their electrocatalytic performance. This paper aims to review the physicochemical concepts, structures, and recent advances on kinetic parameters for lanthanum‐based perovskites for catalytic OER. First, advances on mechanisms and descriptors that govern general perovskites will be discussed in detail. Next, the current results for lanthanum cobaltite (LaCoO3), nickelate (LaNiO3), ferrite (LaFeO3), manganite (LaMnO3), and their derivations will be provided. Moreover, the existing results on less explored lanthanum perovskites for catalytic OER (LaCrO3, LaCuO3, LaVO3, and LaTiO3) will be also presented. The impacts of structural defects, orbital occupancy, materials morphology, and composition on the perovskite electrocatalytic performance will be assessed for each case. Finally, emerging trends for lanthanum‐based perovskites will be provided.

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