Tuning the Hydrogen Evolution Reaction on Metals by Lithium Salt

Tuning the electrode–electrolyte interfaces transiently for controlling the kinetics of hydrogen evolution reaction (HER) on metals will be highly intriguing in energetics. Here, the inherent HER activities of polycrystalline platinum (Pt) and gold (Au) electrodes are altered by different lithium salts. The HER activity of Pt is shown to be suppressed by increasing the Li+ ion concentration while inverse effect is observed in Au, and this is verified in different pH (2–13) conditions and also with different counterions (Li+, Na+, ClO4–, Cl–, and bis(trifluoromethanesulfonyl)imide) ion. A mechanistic insight is provided for this observed phenomenon, which has paramount importance in other electrocatalytic processes as well, such as carbon dioxide reduction and nitrogen reduction reactions.