2D Assembly of Confined Space toward Enhanced CO₂ Electroreduction

Rational design of electrocatalysts toward efficient CO 2 electroreduction has the potential to reduce carbon emission and produce value‐added chemicals. In this work, a strategy of constructing 2D confined‐space as molecular reactors for enhanced electrocatalytic CO 2 reduction selectivity is demonstrated. Highly ordered 2D nanosheet lamella assemblies are achieved via weak molecular interaction of atomically thin titania nanosheets, a variety of cationic surfactants, and SnO 2 nanoparticles. The interlayer spacings can be tuned from 0.9 to 3.0 nm by using different surfactant molecules. These 2D assemblies of confined‐space catalysts exhibit a strong size dependence of CO 2 electroreduction selectivity, with a peak Faradaic efficiency of 73% for formate production and excellent electrochemical stability at an optimal interspacing of ≈2.0 nm. This work suggests great potential for constructing new molecular‐size reactors, for highly selective electrocatalytic CO 2 reduction.