Electride-induced interlayer charge transfer enhances single-cluster catalysts for CO₂ electroreduction

Single-cluster catalysts (SCCs) exhibit great potential for tackling the sluggish kinetics and low Faraday efficiency of the CO₂ reduction reaction (CRR) owing to their unique catalytic activity and maximum atom efficiency. However, the development of support materials capable of simultaneously satisfying the dual demands of stability and catalytic activity for SCCs remains challenging. Herein, the electride Ba₂N was introduced to enhance the stability and catalytic performance of trimetallic cluster embedded g-C₂N (M₃) by constructing the novel heterojunction structure (M₃/Ba₂N). Through the synergy of machine learning (ML) and density functional theory calculations, the catalytic mechanism, product selectivity, and key features governing catalytic activity were revealed. The results show that the introduction of the electride can induce significant interlayer charge transfer from Ba₂N to M₃, which effectively enhances thermodynamic stability, promotes CO₂ activation, and regulates catalytic activity and product selectivity of cluster sites. Notably, Fe₃/Ba₂N was predicted to be an effective CRR catalyst with high stability, outstanding activity, and excellent selectivity. More importantly, ML algorithms further revealed that the catalytic activity of SCCs is strongly correlated with the electronic and structural characteristics. The present work develops a new design paradigm for SCCs, furnishing both theoretical guiding principles for support materials selection and a predictive framework for highly efficient CRR electrocatalysts.