Axial Dual Atomic Sites Confined by Layer Stacking for Electroreduction of CO₂ to Tunable Syngas

Arranging atoms in an orderly manner at the atomic scaleto createstable polyatomic structures is a very challenging task. In this study,we have developed three-dimensional confinement areas on the two-dimensionalsurface by creating regional defects. These areas are composed ofvertically stacked graphene layers, where Ni and Fe atoms are anchoredconcentrically to form axial dual atomic sites in high yield. Thesesites can be used to produce tunable syngas through the electroreductionof CO2. Theoretical calculations indicate that the Ni sitesvertically regulate the charge distribution of the adjacent Fe sitesin the layer below, resulting in a lower d-band center. This, in turn,weakens the adsorption of the *CO intermediate and inhibits the productionof H-2 at the Fe site. Our research presents a novel approachfor concentrated creation of dual atomic sites by building a confinement-selectivesurface.