Separation of Hydrogen and Nitrogen Gases with Porous Graphene Membrane

Abstract

We designed a series of porous graphene as the separation membrane of H 2 /N 2 . The selectivity and permeability could be controlled by drilling various nanopores with different shapes and sizes. The mechanisms of hydrogen and nitrogen to permeate through the porous graphene are different. The small nanopore (pore-11) can only allow the hydrogen molecules to permeate due to the size restriction. In the systems of bigger nanopores (e.g., pore-13, pore-14, etc.), where the pore size is big enough to allow nitrogen molecules to permeate without any restriction, we observed more permeation events of nitrogen than that of hydrogen molecules. The reason is that the van der Waals interactions with the graphene membrane make the nitrogen molecules accumulate on the surface of graphene. When the pore size further increases, the flow of hydrogen molecules exhibits the linear dependence on the pore area, while there is no obvious correlation between the flow of nitrogen molecules and the pore area.

Selective Ionic Transport through Tunable Subnanometer Pores in Single-Layer Graphene Membranes

“…Regardless, stabilization of pore size allows for a tighter distribution of pore diameters than that possible in case of a linear growth rate, and also results in subnanometer pores that are predicted to exhibit the selectivity required for nanofiltration, desalination, and gas separation. [1][2][3][4][5] To investigate transport across the created pores, we fabricated a graphene composite membrane (GCM) by direct transfer of graphene from copper foil 36 to a polycarbonate track etch (PCTE) membrane support 24 ( Fig. 5a and Fig.…”

Thermodynamic Effects of Nanotechnological Augmentation of Hydrogen Fuel Cells

“…Porous graphene 15 is produced as a single sheet of carbon, bonded in a planar, hexagonal structure, with several carbon atoms removed to create a "pore", shown in figure [3] 16,17 which can be used as a nanofilter 18 . Due to graphene's open structure, electrons and protons can freely pass through the lattice with minimal resistance, while restricting the flow of larger molecules, which may only pass through the pores 6 . .…”

“…The Hydrogen ions (Protons) are drawn through the membrane of the system toward the cathode, which with the Oxygen molecules, produce water as a waste product. (6) Water is expelled from the system.…”

Nanoporous graphene oxide membrane and its application in molecular sieving

“…All molecular dynamic simulations were performed in an NVT enable to gases [7]. However, several studies have suggested that graphene has the potential to induce highly selective transport by generation of pore defects [8][9][10][11][12][13][14], in which atoms can be removed from the graphene lattice to create pores of specific size and geometry.…”