Electronic Regulation of Nickel Single Atoms by Confined Nickel Nanoparticles for Energy‐Efficient CO 2 Electroreduction

Abstract Modulating the electronic structure of atomically dispersed active sites is promising to boost catalytic activity but is challenging to achieve. Here we show a cooperative Ni single‐atom‐on‐nanoparticle catalyst (NiSA/NP) prepared via direct solid‐state pyrolysis, where Ni nanoparticles donate electrons to Ni(i)−N−C sites via a network of carbon nanotubes, achieving a high CO current density of 346 mA cm −2 at −0.5 V vs RHE in an alkaline flow cell. When coupled with a NiFe‐based anode in a zero‐gap membrane electrolyzer, the catalyst delivers an industrially relevant CO current density of 310 mA cm −2 at a low cell voltage of −2.3 V, corresponding to an overall energy efficiency of 57 %. The superior CO 2 electroreduction performance is attributed to the enhanced adsorption of key intermediate COOH* on the electron‐rich Ni single atoms, as well as a high density of active sites.