Size-effect on Ni electrocatalyst: The case of electrochemical benzyl alcohol oxidation

The nanoparticles (NPs) of Ni with different sizes endows its distinctive physical and chemical properties, which represents a typical strategy for the development of high-performance catalysts. However, the size effect of metallic Ni-NPs on electrocatalytic performance remains ambiguous. Herein, the Ni-NPs with different sizes supported on nitrogen doped carbon (NC) has been synthesized by controlling the pyrolysis temperature, leading to the synthesis of Ni@NC-500 (8.3 nm), Ni@NC-280 (1.9 nm) and Ni@NC-200 (1.0 nm). The electrooxidation of benzyl alcohol (BA) over these nanocatalysts shows the yield of benzoic acid was 99%, 82%, 55% on Ni@NC-280, Ni@NC-200 and Ni@NC-500, respectively. The experimental and theoretical simulation demonstrate that the difference in the adsorption strength of reactant molecules by Ni-NPs is responsible for their different performance, where the Ni@NC-280 exhibits an optimal adsorption configuration between Ni@NC-280 electrode and BA. This work provides a new angle for designing and synthesizing efficient electrocatalysts, which may be extended to the exploration of various promising electrocatalytic systems.

Automated summary

In this study, different-sized Ni nanoparticles supported on nitrogen-doped carbon were synthesized by controlling the pyrolysis temperature. The electrooxidation of benzyl alcohol over these nanocatalysts showed varying performance, which was attributed to the difference in adsorption strength of reactant molecules.