A mechanistic study of CO₂ gas hydrate formation in a mesoporous zeolite.

Abstract

Carbon Capture Utilization and Storage (CCUS) is essential for mitigating climate change and enabling a low-carbon future. Gas hydrate formation within confined space offers a promising strategy to advance gas hydrate technology, including CCUS. This study employs the first mesoporous zeolite ZMQ-1, with 2.3 nm-wide channels, as a scaffold for CO₂ hydrate formation. CO₂ adsorption experiments were conducted on pre-humidified ZMQ-1 at 275 K and pressures up to 3 MPa, with hydrate formation confirmed by identifying specific vibrational modes of CO₂ through Fourier Transform Infrared (FTIR) spectroscopy. Hydrate formation occurred under mild conditions (1.3 MPa and 275 K) with an extremely short induction time of just 2 min at an optimal water-to-zeolite ratio (Rw = 2). The mesoporous zeolite-gas hydrate system demonstrated high volumetric CO₂ capacity, reaching 151 wt.% (176 v/v). Comparative experiments with calcined (open-pore) and non-calcined (blocked-pore) zeolite revealed the spatial and temporal distribution of hydrate formation, providing insights into the role of pore confinement. These findings position mesoporous ZMQ-1 as a promising platform for CO₂ storage via hydrate formation, with strong potential for future development in scalable and energy-efficient CCUS technologies.