Dual Single‐Atom Catalysts Unveiling Active Sites for Enhanced Ethylene Methoxycarbonylation

Abstract

ABSTRACT Designing heterogeneous catalysts with well‐defined structure remains crucial for identifying true active sites and achieving superior performance. Here, we report a series of Ru‐based dual single‐atom catalysts (DSACs) constructed on TiO 2 , in which catalytically inert second metals (Zn, Mn, Mo, In) delicately modulates the electronic structure of Ru. Among them, Ru 1 Zn 1 /TiO 2 with most electron‐deficient Ru site exhibits highest activity and durability for acid‐free ethylene methoxycarbonylation (EMC) with a turnover frequency of 1403 h −1— one to two orders of magnitude higher than previously reported Ru‐based catalysts, ranking among the most efficient heterogeneous EMC catalysts. Benefiting from well‐defined and fine‐tuned structure of DSACs, an unambiguous establishment of the structure‐activity relationship has been achieved, pinpointing electron‐deficient Ru δ+ species as the true active sites for the EMC reaction. Further DFT calculations reveal the electronic coupling in Ru‐Zn site optimizes the d‐band center near the Fermi level, and facilitates the adsorption and activation of reactants, thereby reducing the energy barrier for the C‐C coupling step. This work establishes a general strategy for constructing bimetallic single‐atom catalysts as precise model systems for elucidating active sites and guiding the rational design of efficient and stable catalysts for carbonylation and related transformations.