Electrocatalysis of the hydrogen oxidation reaction on carbon-supported bimetallic NiCu particles prepared by an improved wet chemical synthesis

- Incipient wetness impregnation method followed by freeze-drying is applied.
- Average size of NiCu particles is around 30 nm.
- Dependence of catalytic activity on Cu fraction has maximum with Cu fraction 5%.

Carbon supported Ni1 − xCux/C catalysts with different Ni:Cu atomic ratios comprising ca 30 nm particles uniformly distributed over the surface of carbon support were prepared by the incipient wetness impregnation followed by freeze-drying. The catalysts have been characterized by X-ray powder diffraction, transmission electron microscopy and cyclic voltammetry. The electrocatalytic activities of Ni1 − xCux/C catalysts in the hydrogen oxidation reaction in alkaline medium were examined with linear sweep voltammetry. It was found that addition of Cu at low fractions significantly improves the electrocatalytic activity of Ni in the hydrogen oxidation reaction, while increasing the Cu fraction above 5% results in its attenuation. The observed behavior of NiCu catalysts is compared to the literature data and tentatively explained by the influence of Cu on the energy of hydrogen adsorption on Ni.