Boosting electrocatalytic hydrogen evolution via partial oxidation of rhenium through cobalt modification in nanoalloy structure.

Although the theoretical electrocatalytic activity of rhenium (Re) for the hydrogen evolution reaction is comparable to that of platinum, the experimental performance of reported rhenium-based electrocatalysts remains unsatisfactory. Herein, we report a highly efficient and stable electrocatalyst composed of rhenium and cobalt (Co) nanoalloy embedded in nitrogen-doped carbon film (ReCo@NCF). The ReCo@NCF electrocatalyst exhibited remarkable hydrogen evolution performance, with an overpotential as low as 30 ± 3 mV to reach a current density of 10 mA cm. In addition, the ReCo@NCF demonstrated exceptional stability over several days at a current density of 150 mA cm. Theoretical calculations revealed that alloying cobalt with rhenium altered the electronic structure of the metals, causing partial oxidation of the superficial metal atoms. This modification provided a balance for various intermediates' adsorption and desorption, thereby boosting the intrinsic activity of rhenium for hydrogen evolution reaction. This work improves the electrocatalytic performance of rhenium to its theoretical activity, suggesting a promising future for rhenium-based electrocatalysts.