First Principles Study of Gas Adsorption Dynamics on Pristine and Defected Graphene

We present the results of ab initio calculations of gas adsorption processes on graphene. Static density functional theory framework is used to obtain adsorption energies of several species on a Stone-Wales defected graphene monolayer. The Van der Waals interaction is taken into account by a semi-empirical correction. Sites closer to the defect are found to induce stronger adsorption compared to sites further away, where the graphene crystal structure is intact. The Car-Parrinello ab initio molecular dynamics simulations are performed at high temperatures. CH₃ is found to be stably physisorbed or chemisorbed at 300 K.