Zeolites are among the most widely employed catalysts in the (petro-)­chemical industry. However, due to their elaborate microporous network, they are prone to diffusion limitations and deactivation. Several modification methods have been proposed to overcome these limitations, each exhibiting their benefits. In this work, two of the most promising strategies were combined, i.e., limiting the length of one of the crystal axes during synthesis to achieve a platelike morphology and introducing mesoporosity, creating a hierarchical platelike H-ZSM-5. The platelike morphology was obtained by adding urea as a growth modifier to the synthesis mixture, and mesopores were introduced in the platelike H-ZSM-5 through etching with a NaOH/TPAOH mixture. As a benchmark, the same etching procedure was applied to a commercial ZSM-5 counterpart. These materials were tested in the n-butanol dehydration, where the platelike morphology exhibited an improved catalytic performance, significantly increasing the activity per acid site and stability, and slightly increasing the selectivity toward the butenes. The generation of mesopores in commercial ZSM-5 also increased the activity per acid site but reduced the catalyst’s stability, likely due to an increased amount of Lewis acid sites upon etching. When applying the same modification method to the platelike H-ZSM-5, much larger mesopores and some macropores were observed. These further increased the stability of the catalyst but barely affected the activity per acid site, presumably due to the already optimized catalytic performance of the platelike H-ZSM-5.

ZSM-22 zeolites with different Si/Al ratios (38, 50, 80) were prepared via a hydrothermal synthesis method, investigated for the catalytic dehydration of 1,3-butanediol (1,3-BDO) to butadiene (BD) at 300 °C. The catalytic performance of the synthesized materials was related to their properties and compared to a commercial ZSM-22 zeolite (Si/Al = 30). ZSM-22 (50) exhibited a quick decline in conversion, a lower BD selectivity, and higher propylene selectivity compared to the other materials, which could be attributed to the presence of strong Lewis acid sites and silanol nests. The Lewis sites favor the cracking of the intermediate 3-buten-1-ol (3B1OL) into propylene, while the silanol nests interact with the free hydroxyl group of 3B1OL, potentially inhibiting further dehydration towards BD. The highest initial BD yield of 74% was observed over ZSM-22 (80), while the highest initial BD productivity of 2.7 g_BD·g⁻¹_cata·h⁻¹ was achieved over ZSM-22 (38). After 22 h time on stream (TOS), c-ZSM-22 and ZSM-22 (38) outperformed previously reported catalysts from the literature, with productivities amounting to 1.3 g_BD·g⁻¹_cata·h⁻¹ and 1.2 g_BD·g⁻¹_cata·h⁻¹, respectively, at a site time of 6.6 mol_H+·s·mol⁻¹_1,3-BDO.

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 minutes 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 hyrate formation, with strong potential for future development in scalable and energy-efficient CCUS technologies.