The Neglected Significant Role for Graphene-Based Acetylene Hydrochlorination Catalysts - Intrinsic Graphene Defects

In the present work, density functional theory(DFT) calculations at M062X/cc-pVDZ level were performed aim to investigate the activity of defective graphenes catalyze acetylene hydrochlorination reaction. Owing to the narrowed HOMO-LUMO energy gaps, the adsorption ability of C2H2 and HCl on three kind of defective graphenes(mono-vacancy graphene(MVG), di-vacancy graphene(DVG) and Stone-wales defect graphene(SWDG)) were all enhanced compared with perfective graphene(PG). Meanwhile, the adsorption strength of the two adsorbates decreased followed by the order of DVG > MVG > SWDG, and the strength of C2H2 is tougher than HCl adsorb on MVG and DVG, but opposite in SWDG. The reaction mechanisms are similar and reacted at the site of the mutual bond C-5-C-6 which belongs to 5-MR and 6-MR. MVG possess the lowest activation barrier of 39.46 kcal/mol, lower than DVG and SWDG. Hence, the catalytic contribution of graphene defects for acetylene hydrochlorination reaction should not be ignored.