Exploring Spin Dynamics in Diatomic Co₂ Catalysts on Graphyne for Enhanced CO Electroreduction

Investigating spin dynamics in electrocatalysis is crucial for the rational design of paramagnetically heterogeneous catalysts. Utilizing spin-polarized density functional theory (DFT) calculation, herein, we identify spin dynamic of diatomic Co₂-supported γ-graphyne (Co2-GY) catalysts during the process of CO electroreduction ( eCORR ), focusing on the effect of the applied potential and acidy on spin dynamic and catalytic performance. Specially, the obtained Co2-GY shown a new efficient C2 pathway of CH2* + CHO* coupling mechanism, resulting in the optimal CH3CH2OH product with ∆G of 0.50 eV and the selectivity of 99.99% under alkaline condition. Under acidic media, Co2-GY exhibited the optimal C1 product (CH3OH) with ∆G of 0.27 eV and the selectivity of 99.99%. During CO electroreduction, the reaction environment (pH and applied potential) influences spin dynamics in catalyst-reactant systems, affecting the spin transition of diatomic Co2 active sites among four magnetic states: ferromagnetic, antiferromagnetic, paramagnetic, and diamagnetic. These finding will be helpful for rational design of transition-metal heterogeneous catalysts.