N-doped porous graphene for carbon dioxide separation: a molecular dynamics study

Abstract

Using molecular dynamics simulations, it is shown that N-doped porous graphene membrane can efficiently separate CO 2 from the CO 2 /CH 4 mixture. The effects of pore rim modifications, N-doping sites, initial gas pressure, and feed gas compositions on CO 2 separation performance of N-doped porous graphene membrane are also examined. It is found that gas permeability increases with increasing initial gas pressure or the feed gas percentages. Pore rim modifications with nitrogen atoms (pyridinic N) can significantly improve the selectivity of CO 2 over CH 4 owing to the enhanced electrostatic interactions compared to the unmodified one, and the all-N-modified pore-16 shows the highest CO 2 selectivity over CH 4 (*29). Doping N atoms on the graphene sheets (quaternary N) has little effect on the CO 2 selectivity. Our study demonstrates that the N-doped porous graphene is an excellent candidate for CO 2 separation, which may be beneficial for the realization of a low carbon society.

Recent advances in nanoporous graphene membrane for gas separation and water purification

“…They found a high selectivity on the order of 10 8 through an N-functionalized pore and an extremely high selectivity on the order of 10 23 through an all-H passivated pore for separating H 2 /CH 4 mixtures with a high H 2 permeance. Afterward, several theoretical works were conducted to further confirm that the NPG membranes could achieve high permeability and selectivity for gas separations [23,[52][53][54][55]. Due to the difficulties in experimental works, Fig.…”

Influence of filling atoms on radial collapse and elasticity of carbon nanotubes under hydrostatic pressure

“…Simulations have been carried out using a commercial software package called Materials Studio (MS) developed by Accelrys Software. The interaction among atoms is simulated using the condensed-phase optimized molecular potential for atomistic simulation studies (COMPASS) force field method [35]. The COMPASS force field is a parametrized, tested, and validated first ab initio force field, which enables an accurate prediction of various gas-phase and condensed-phase properties of most of the common organic and inorganic materials [36,37].…”

Inhibition effect of a non-permeating component on gas permeability of nanoporous graphene membranes

“…Several researchers have conducted the studies on the gas separation with NPG membranes using MD simulations. [34][35][36][37][38][39][40][41][42][43] The molecular adsorption on the graphene surface has a great impact on the gas permeation through the NPG membranes. Du et al 42 designed a series of porous graphene membranes for separating the H 2 /N 2 gas mixture and reported that the superior permeation of the N 2 molecules over that of the H 2 molecules when the pores were large enough owing to the strong adsorption of the N 2 molecules on the graphene surface.…”