Adsorption of small hydrocarbons on pristine, N-doped and vacancy graphene by DFT study

In this paper, the adsorption mechanisms between different species (CH3, CH4, C2H2, C2H4, C2H6, and C6H6) and the carbon-based materials (pristine graphene, N-doped graphene, and vacancy graphene) during the chemical vapor infiltration process were systematically studied using the density functional theory. The optimized adsorption configurations were obtained by using Dmol3 code in Material Studio. The adsorption energies, Mulliken atomic charges, density of states, and charge density differences of the adsorption process were analyzed. It showed that the CH3 is chemisorbed, while the other species (CH4, C2H2, C2H4, C2H6, and C6H6) are weak physisorbed on pristine graphene, N-doped graphene and vacancy graphene. In addition, the introduction of nitrogen dopant and vacancy defect into the pristine graphene does not significantly affect the adsorption mechanisms between small hydrocarbons and graphene.