Tweaking the composition of NiMoZn alloy electrocatalyst for enhanced hydrogen evolution reaction performance

Nickel-based alloy catalysts are promising candidates to replace noble metal materials for electrocatalytic hydrogen evolution reaction (HER), but the performance of the alloy systems still needs to be improved to effectively substitute noble metal catalysts, such as platinum. Here we report a detailed study of the controlled deposition of NiMoZn ternary alloy electrocatalysts and we subsequently investigate the influence of chemical composition on the HER reactivity. We have identified the essential role of Zn for boosting the intrinsic electrocatalytic performance and revealed the optimum Zn concentration in the alloy. While the low concentration of Zn facilitates the charge transfer process, massive Zn deposition in the alloy results in a strong inhibition of proton adsorption on the surface of the electrocatalysts. The NiMoZn alloy electrocatalyst with a Zn concentration of 1-3 at% shows an extremely high activity for HER, which is significantly higher than that of most non-noble metal electrocatalysts. Moreover, the alloy with 2 at% of Zn exhibits an excellent stability in acid conditions, featuring the NiMoZn alloy a promising candidate to replace noble metal electrocatalyst for water splitting process. (C) 2014 Elsevier Ltd. All rights reserved.