Enhanced selectivity and stability towards CO₂ reduction of sub-5 nm Au NPs derived from supramolecular assembly

We report three well-defined types of Au nanoparticles (NPs) protected by rigid macrocyclic cucurbit[n]uril (CB[n]) (CB[n]-Au), which are prepared via the supramolecular self-assembly of the precursors. CB[n]-Au shows excellent catalytic activity and selectivity, with a performance that can be maintained for up to 72 h in the electroreduction of CO₂ to CO. The effects of the structural features of different CB[n]s on the electrocatalytic performance of the Au NPs have been revealed for the first time.