Computational screening of single-atom catalysts supported on triazine-based graphite carbon nitride for 1,2-dichloroethane dechlorination

In this study, we systematically investigated the performance of eight transition metal atom-loaded triazine-based graphitic carbon nitride (TM@TGCN) for the catalysis of 1,2-dichloroethane (1,2-DCE) dechlorination reaction (DCEDR) by density functional theory calculations. Through the five-step screening method, the suitable catalysts, respectively, applicable to the generation of vinyl chloride (CH2CHCl), ethylene (CH2CH2), and ethane (CH3CH3) were finally determined. The limiting potential of Fe@TGCN for reducing 1,2-DCE to CH3CH3 is lower, at -0.47 V (gauche-C2H4Cl2) and -0.50 V (trans-C2H4Cl2), respectively. The activity mechanism indicates that Fe@TGCN is at the vertex of the volcano plot, confirming that the intensity of its interaction with the reactants is in optimal equilibrium. In addition, we further examined the influence of hydroxyl modification on the selectivity of DCEDR. The results show that hydroxyl modification significantly weakens the adsorption strength of intermediates (such as *CH2CH2Cl) through a steric hindrance effect and electron delocalization, as well as reduces the desorption energy of CH2CH2 and enhances its selectivity. This study provides theoretical guidance for the rational design of DCEDR electrocatalysts and reveals the key role of ligand modification strategies in regulating the reaction pathway.