Enhanced Hydrogen and Methane Storage in β-Zeolite Templated Carbons: Structural and Functional Insights

This study explores the hydrogen and methane adsorption properties of β-zeolite-templated carbons (β-ZTCs). It evaluates the effects of chemical and thermal post-synthesis treatments on their structural, textural, and surface functionalities. Modifications to surface oxygen functionalities led to slight changes in carbonyl, lactone, and phenol species, alongside a minor reduction in long-range pore order. Despite these alterations, the microporous nature of β-ZTCs remained dominant, with minimal impact on H₂ adsorption at 77 K. The materials demonstrated high storage capacities, achieving 6.4 wt% for H₂ and 18.7 wt% for CH₄, with volumetric uptakes of 40 g/L (H₂, 77 K, 40 bar) and 110 g/L (CH₄, 298 K, 50 bar), comparable to compressed gas systems. The results highlight that the treatments had a limited effect on pore surface structure and microporosity (∼90 % of total pore volume), significantly contributing to enhanced gas uptake. At room temperature, β-ZTCs exhibited a strong affinity for CH₄ over H₂, with adsorption ratios nearing 10 across the pressure range, underscoring their potential for gas separation. These results highlight the suitability of β-ZTCs for sustainable energy storage and separation technologies, with the post-synthesis treatments providing insights into performance tunability.