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

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.