One-pot synthesis of novel porous carbon adsorbents derived from poly vinyl chloride for high methane adsorption uptake

Owing to the increasing interest in the production of “turquoise” hydrogen, various methods for capturing and recycling unreacted methane as a reactant have been reported. Porous carbon adsorbents can efficiently capture large amounts of methane based on the pore structure and reduce the adsorption column size due to its low density. Herein, we report a one-pot synthesis for preparing porous carbon adsorbents by thermally treating poly(vinyl chloride) or chlorinated poly(vinyl chloride)/KOH admixtures under Ar flow and characterize their methane adsorption properties. The Ar adsorption measurements indicated that the prepared porous carbon adsorbents have uniform pore sizes (between 0.4 and 0.8 nm), in addition to a large Brunauer–Emmett–Teller (BET) surface area and micropore volume. The unique textural properties contributed significantly to the superior methane adsorption performances. In particular, the cPVCK800 sample exhibited the highest CH₄ adsorption uptake of 3.17 mmol/g at 25 °C. Density functional theory calculations revealed that functionalized pore structures also significantly improve the CH₄ adsorption properties.