Boosting selective CO2 reduction via strong spin-spin coupling on dual-atom spin-catalysts.

Achieving high selectivity in electrochemical conversion of carbon dioxide (CO2) into valuable products remains a significant challenge. This study investigates the influence of spin states on dual-atom catalysts within two-dimensional metal-organic frameworks (2D-MOFs) and zero-dimensional molecular metal complexes (0D-MMCs), emphasizing their role in the selective electrocatalytic reduction of CO2. Utilizing first-principles calculations, we systematically evaluate dual-atom spin-catalysts (DASCs) TM2S4(NH)2(C6H4)2 0D-MMC and TM2S4(NH)2C4 2D-MOF for CO2 reduction reactions (CO2RR) across various spin states: antiferromagnetic (AFM), ferromagnetic (FM), and non-magnetic (NM). Our analysis confirms that, beyond successfully designing and screening highly active catalysts, the selectivity for various C1 products in CO2 reduction can be readily adjusted by DASCs via spin-spin coupling. Specifically, Mn2 and Fe2 2D-MOF DASCs with an AFM ground state are more inclined to produce formic acid, while their FM counterparts favor the formation of methane, surpassing formic acid among others. Additionally, we demonstrate that 0D-MMCs, as molecular units of 2D-MOFs, achieve comparable catalytic performance. Combining theoretical insights with machine learning highlights the crucial role of electronic and geometric descriptors in the catalytic performance. Our work establishes the correlation between spin-spin coupling and highly selective CO2 reduction in DASCs, offering an effective strategy for designing tunable and efficient electrocatalysts.