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 magnetically heterogeneous catalysts. Utilizing spin-polarized density functional theory calculation, herein, the spin dynamic of diatomic Co-supported gamma-graphyne (Co-2-GY) catalysts during the process of CO electroreduction (eCORR) is identified, focusing on the effect of the applied potential and acidity on spin dynamic and catalytic performance. In particular, the obtained Co-2-GY shows a new efficient C-2 pathway of CH2* + CHO* coupling mechanism, resulting in the optimal CH3CH2OH product with increment G of 0.50 eV and the selectivity of 99.99% under alkaline conditions. Under acidic media, Co-2-GY exhibits the optimal C1 product (CH3OH) with increment G of 0.27 eV and a 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 Co-2 active sites among four magnetic states: ferromagnetic, antiferromagnetic, paramagnetic, and diamagnetic. These findings will be helpful for the rational design of transition-metal heterogeneous catalysts.