A density functional theory study on the performance of graphene and N-doped graphene supported Au3 cluster catalyst for acetylene hydrochlorination

Density functional theory (DFT) calculation was used to investigate the mechanism of Au-3 clusters, separately supported on pure graphene (Au-3/graphene) and one graphitic N-doped graphene (Au-3/N-graphene). These supported Au-3 clusters were used to catalyze acetylene hydrochlorination. Results show that the graphene supporter could obviously enhance the adsorption of reactants. Also, N-atom doping could broaden the energy gap between the HOMO of graphene and the LUMO of Au-3, leading to the significantly attenuated interaction between the Au-3 cluster and graphene by more than 19 kcal/mol (1 cal = 4.184 J). The two catalysts possessed extremely similar reaction mechanisms with activation energy values of 23.26 and 23.89 kcal/mol, respectively. The calculated activation barrier declined in the order of Au-3 < Au-3/N-graphene < Au-3/graphene, suggesting that Au-3/N-graphene could be a potential catalyst for acetylene hydrochlorination.