Vacancy-Defect Single-Atom Catalysts for Tandem CO2 Electroreduction and Carbonylation Reactions from Flue Gas

Tandem CO2 reduction with carbonylation reactions represents a promising approach to convert greenhouse gases into valuable chemicals. Herein, we propose a universal "N/O mixed pre-coordination pyrolysis" strategy to construct vacancy-defect single atom catalysts (Ni-1-, Mn-1-, Fe-1-, Co-1-, and Cu-1-NC) with M-N-3 coordination microenvironment. This vacancy-defect endows Ni-1-NC with excellent performance for CO2 electroreduction, achieving a CO faradaic efficiency exceeding 90% across a wide range of current densities up to 300 mA cm(-2). The generated CO was directly fed to carbonylation reactions, producing organic chemicals with yields of up to 91.7% and leading to produce 1.13 g of benzophenone in a single run. For the first time, the membrane separation CO2 system was integrated with tandem catalytic system, enabling direct utilization of flue gas for benzophenone synthesis with a 76.6% yield. This work offers a sustainable, eco-friendly method for CO2 separation and utilization by feeding industrial waste gas to carbonylation reactions.