Toward Rational Design of Dual-Metal-Site Catalysts: Catalytic Descriptor Exploration

Dual-metal-site catalysts (DMSCs) have emerged as a frontier in heterogeneous catalysis, while the underlying relationships connecting their dual-site synergistic effects on catalytic performance remain unclear. Here we present a comprehensive first-principles study of O2 activation and CO oxidation on a series of N-coordinated DMSCs. We discovered that the N3-coordinated-adjacent dual-metal model has stronger synergistic and dynamic effects, leading to much higher catalytic activity than others investigated. Based on this model, detailed comparisons of various metal combinations (M = Fe, Co, Ni, Cu, and Pt) show that Fe-containing combinations are generally more active than others. In particular, the Fe–Ni combination, owing to its preferential coadsorption of CO+O2 and highest activity is identified as the most promising candidate for CO oxidation. To explore some universal descriptors for catalytic performance of different combinations, various relationships (50 in total) were systemically studied. It is found that the designed electronic/spectral descriptors of charge transfer, average charge on metals, average d-orbital center on metals, and stretching vibrational frequency of reactants may reflect the binding ability/stability of O2 as lone reactant. However, for multiple reactants (CO+O2), the binding stability/reactivity of the key-species (O2) descriptor has better performance. The transferability of such descriptors to multimolecular catalysis was confirmed by applying them to NO oxidation. These novel descriptors highlight the importance of structure–activity relationships under reaction conditions, thus providing potential design strategies for high-efficiency DMSCs.