H[formula omitted] adsorption on Li and Ca functionalized few layers graphene: Insights from grand canonical Monte Carlo studies.

Functionalized graphene with alkali or alkaline metals is a potential candidate for H 2 adsorption and storage at pressures equal to or below 100 bar. A rigorous study was conducted to understand the effect of functionalizing Few Layers Graphene (FLG) with Li and Ca atoms on the hydrogen uptake and its interaction with pressure, temperature, and pore width. The results show a complex interplay between the added weight of the functionalized atoms and the increased solid–fluid interactions finding a nonlinear relationship between the degree of functionalization and the adsorption uptake. It was found that Li-FLG and Ca-FLG can match and exceed 65 mg H 2 /g at low temperatures and high pressure. • Monte Carlo simulations were utilized to investigate the impact of Li and Ca functionalization on H 2 uptake in FLG. • Functionalization of Li and Ca can increase H 2 adsorption up to 10 times compared to pristine FLG. • FLG functionalized with Li and Ca can reach an adsorption of 65 mg/g with pores wider than 14 Å. • Ca can replace Li at low metallic coverages, keeping a similar H 2 uptake. [ABSTRACT FROM AUTHOR]