Molecular Fence Cu-based Catalyst for CO2 Hydrogenation to CO with High Activity and Durability

The conversion of CO ₂ into high-value syngas (CO and H ₂ ) using Cu-based catalysts has garnered considerable interest. However, these catalysts deactivate rapidly due to Ostwald-ripening and thermal aggregation. Herein, we proposed to encapsulate Cu-cluster into mMOR zeolite for engineering a separation-site catalyst Cu@mMOR. In the reverse water-gas shift reaction (RWGS), mMOR zeolite of Cu@mMOR directly captures and then activates CO ₂ , and simultaneously served as a molecular fence to prevent CO ₂ contact with Cu-clusters surrounding with small pore of mMOR (< 3.0 Å) channels. These encapsulated Cu-clusters in mMOR possessed considerable Cu vacancies, which significantly facilitate H ₂ heterolytic dissociation, transferring H ^* species towards activated CO ₂ on mMOR and converting them into CO. This separation-site strategy efficiently increased catalytic activation while intelligently altering the CO ₂ reaction pathway, preventing Cu from thermal agglomeration and Oswald ripening in the catalyst. Consequently, Cu@mMOR attained a space-time yield of CO as high as 3290 mmol g _cat ⁻¹ h ^− 1 , with catalytic stability extending up to 788 hours. This performance of Cu@mMOR was markedly superior to that of recently reported catalysts.