Searching for DFT-based methods that include dispersion interactions to calculate the physisorption of Hon benzene and graphene.

Abstract

Accurate modeling of hydrogen storage in nanoporous carbon materials requires precise description of the interaction between H2 molecules and graphite-like pore surfaces, where dispersion forces are dominant. This computational study benchmarked several DFT methods incorporating dispersion corrections against the high-accuracy CCSD(T) reference for H2 on benzene, and against experimental adsorption data for H2 on graphene. Among the methods examined, B97D, RVV10, and PBE+DCACP reproduced the CCSD(T) interaction energy curves for the H2–benzene system with notable fidelity. For graphene, the rev-vdW-DF2, PBE-XDM, PBE-D2, and RVV10 functionals yielded adsorption energies in close agreement with experimental values. These findings identify computationally tractable DFT approaches that balance accuracy and cost for large-scale hydrogen storage simulations.

Mechanism

Dispersion-dominated physisorption of H2 on benzene and graphene was evaluated by comparing interaction energy curves from multiple DFT dispersion-correction schemes against CCSD(T) reference calculations and experimental adsorption data.