Adsorption of sulfur dioxide and mixtures with nitrogen at carbon nanotubes and graphene: molecular dynamics simulation and gravimetric adsorption experiments

Abstract

The adsorption of sulfur dioxide (SO\(_{2}\)), nitrogen (N\(_{2}\)) and mixtures of both on carbon nanotubes (CNTs) and graphene was studied by molecular dynamic simulation. Experimental results from gravimetric adsorption of SO\(_{2}\) and N\(_{2}\) on CNTs are compared to simulated data. CNTs with a rigid and a flexible model and the diameters 1.48 and 2.69 nm were simulated. For graphene, SO\(_{2}\) and N\(_{2}\) rigid models were applied. Besides the CNT diameters, different system temperatures, compositions of SO\(_{2}\)/N\(_{2}\) mixtures were considered for selected cases of CNTs and graphene. By examining the local SO\(_{2}\) and N\(_{2}\) densities on the CNTs and graphene, adsorption could be observed. SO\(_{2}\) shows an enhanced adsorption compared to N\(_{2}\) on both CNTs and graphene. By varying the starting configurations of the simulation, different system pressures could be achieved, which allowed the determination of adsorption isotherms at different temperatures.