▎ 摘　　要

Porous graphene (PG) is an important candidate material for energy gas adsorption and storage due to its large specific surface area and low mass. Herein, based on first-principles density functional theory, the adsorption performances of PG and titanium-modified porous graphene (Ti-PG) systems on methane (CH4) molecules are investigated. It is discovered that the optimal adsorption position of a single CH4 molecule on PG is the center C-ring pore, and the adsorption energy is -0.228 eV. In the Ti-PG system, the best position for Ti atom modification is the PG center pore, with a binding energy of -3.603 eV. When two Ti atoms modify the PG system, 24 CH4 molecules can be adsorbed on both sides, the adsorption amount of CH4 can reach 54.7 wt%, and the average adsorption energy is -0.207 eV. After the adsorption of CH4 molecules, the electrostatic interaction between the overall electronegative CH4 molecules and the electropositive Ti atom, the electrostatic interaction between the electropositive surface CH4 molecules and the PG substrate, and the van der Waals force due to the polarity of CH4 molecules create synergistic effects, which improve the CH4 adsorption performance of the Ti-PG system.