Single metal atoms regulated flexibly by a 2D InSe substrate for CO₂ reduction electrocatalysts

The CO₂ electroreduction reaction (CRR) is impeded by the low selectivity and high limiting potential of catalysts. Embedding single metal catalysts (SMCs) in a two-dimensional substrate is a promising strategy to address these issues. Herein, we design a novel type of SMC based on two-dimensional InSe and transition metal atoms (M@2DInSe) using density functional theory calculations. Different from the known SMCs on graphene, TiC, and TiN, the adsorption energies of ∗CO and ∗COOH intermediates on most of the M@2DInSe systems obey the linear relationship established on transition metals, with the results on few candidates deviating from the relationship significantly. Besides, the adsorption energy values of ∗CO/∗COOH on M@2DInSe systems are closer to the values on Cu(111), compared to their bulk counterparts. These characters originate from the hybridization between InSe and d-/s-bands of metal atoms. These properties allow us to quickly screen the catalytic reactivity of M@2DInSe and thus can accelerate the selection of the optimal candidates for CO, HCOOH, H₂, and CH₄ production. Our results provide a reasonable material design scheme for further theoretical research and propose promising candidates with high activity and selectivity for experimental work.