IrMo Nanocluster-Doped Porous Carbon Electrocatalysts Derived from Cucurbit[6]uril Boost Efficient Alkaline Hydrogen Evolution

Electrocatalysts based on noble metals have been proven efficient for high-purity hydrogen production. However, the sluggish kinetics of the hydrogen evolution reaction (HER) in alkaline media caused by high water dissociation energy largely hampers this electrochemical process. To improve the electrocatalytic activity, we fabricate an effective porous carbon matrix derived from cucurbit[6]uril using a template-free method to support iridium-molybdenum (IrMo) nanoclusters. As proof of concept, the resulting IrMo-doped carbon electrocatalyst (IrMo-CBC) was found to boost the alkaline HER significantly. Owing to the unique in-plane hole structure and the nitrogen-rich backbone of cucurbit[6]uril as well as the ultrafine IrMo nanoclusters, IrMo-CBC exhibits pronounced alkaline HER activity with an extremely low overpotential of 12 mV at 10 mA cm^-2, an ultrasmall Tafel slope (28.06 mV dec^-1), a superior faradic efficiency (98%), and a TOF of 11.6 H₂ s^-1 at an overpotential of 50 mV, outperforming most iridium-based electrocatalysts and commercial Pt/C.