Effect of Long-Range Spin-Exchange Interaction in CoPc-Based Two-Dimensional Bimetallic Organic Frameworks for the Electrochemical Reduction of CO₂ to CO

Two-dimensionalmetal-organic frameworks (2D MOFs) are promisingcandidates for the electrochemical reduction of CO2. However,the underlying relationship between spin and catalytic activity hasyet to be fully understood. Herein, we carried out density functionaltheory calculations to investigate the spin-activity correlationfor the electrochemical reduction of CO2 to CO based on2D CoPc-TMTAA frameworks (TM = Cr, Mn, Fe, Co, Ni, Cu, Zn). Our resultsreveal that the central Co atom is the active site for the CO2 reduction reaction, whose spin state can be modulated bythe neighboring ligand metal atoms through the long-range spin-exchangeinteraction. These CoPc-TMTAA frameworks exhibit superior activityfor the reduction of CO2 to CO with limiting potentialsranging from -0.13 to -0.34 V. Furthermore, our calculationsshow a nearly linear relationship between the catalytic activity andthe spin moment variation, suggesting the electronic spin state asa good catalytic descriptor for CoPc-TMTAA framework catalysts. Thesefindings provide important insights into the relationship betweenlong-range spin-exchange interaction and catalytic activity, openinga new avenue for the rational design of efficient 2D bimetallic organicframework electrocatalysts.