The hydrogen evolution reaction in a room temperature ionic liquid: mechanism and electrocatalyst trends

The kinetics and mechanism of the proton reduction reaction in the room temperature ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide ([C(2)mim][NTf2]) was studied at gold, molybdenum, nickel, titanium and platinum electrodes. Significant differences in electrochemical rate constants were observed between the different metals and with the corresponding processes in aqueous solution. The hydrogen evolution mechanism was consistent at all five metals in the ionic liquid, in stark contrast to the known behaviour in aqueous systems.