In the present work, the morphology of L-type zeolite (LTL topology) has been modified in order to evaluate the influence of several protonated-form LTL-zeolites with different morphologies on their stability and catalytic performance in the conversion of glucose into 5-hydroxymethylfurfural (5-HMF). Physico-chemical characterization of the LTL-based catalysts has revealed that the three types of morphologies (needle, short rod and cylinder) are active, providing complete glucose conversion and high 5-HMF yield values. The addition of CaCl2 had a positive influence on the catalytic performance. It was found that morphology influences the textural and acid properties of LTL-zeolites, and hence their catalytic performance. The best catalytic results have been obtained with the NEEDLE-LTL, showing nanoparticles with a length of 4.46 μm and a width of 0.63 μm, which attains a 5-HMF yield of 63%, at 175 °C after 90 min of reaction, and a glucose conversion of 88%. The reusability study has revealed a progressive decrease in 5-HMF yield after each catalytic cycle. Different regeneration methods have been essayed without recovering the initial catalytic activity. The presence of organic molecules in micropores has been demonstrated by TG analysis, which are difficult to remove even after a regeneration process at 550 °C.

Nanoscale cesium-pollucite zeolite (ANA topology) free of organic template is synthesized free of organic template. The crystallization is taken place at mild temperature and pressure (180 C, 22 bar) compared to previous works. Powder XRD analysis reveals that the nanocrystals can be crystallized from a clear precursor solution of 16.5SiO2:1Al2O3:5.3Cs2O:175H2O within 50 h. The resulting nanocrystals exhibit trapezohedron shape and has a Si/Al ratio of 4.11. The nanocrystals possess a mean particle size of 79.4 nm and they are colloidally stable in water. In addition, Perkin condensation of benzaldehyde with acetic anhydride catalyzed by nanosized Cs-pollucite zeolite under non-microwave instant heating condition is also demonstrated and discussed.

Morphological characteristics of zeolites can have significant effects on the catalytic reactions.However, the roles of zeolite morphology on catalytic reactions, particularly Friedel-Crafts acylation of 2-methylfuran, are still not clear. Hence, LTL-type zeolites with different morphologies are prepared by using bamboo leaf bio-silica source where the zeolites are used to elucidate the morphological properties in this acylation reaction. The results show that LTL zeolites with short-rod, cylindrical, stick-like and nanosized shapes can be prepared by simply tuning the water content of the precursor hydrogels and the crystallization time. The morphological properties of LTL zeolites are also found to have pronounced influences on their surface properties (surface areas, pore volumes, number of micropore channels, textural properties) and acidity (amount, strength and type) where these properties affect their catalytic activity in acylation of 2-methylfuran under non-microwave instant heating condition.Furthermore, the influence of temperature and heating time on the kinetics of catalytic acylation of 2-methylfuran, and the catalytic comparative study between nanosized LTL zeolite and several homogeneous and heterogeneous catalysts are also discussed.

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Offretite zeolite synthesis in the presence of cetyltrimethylammonium bromide (CTABr) is reported. The offretite crystals were synthesized with a high crystallinity and hexagonal prismatic shape after only 72 h of hydrothermal treatment at 180 °C. The CTABr has dual-functions during the crystallization of offretite, viz. as structure-directing agent and as mesoporogen. The resulting offretite crystals, with a Si/Al ratio of 4.1, possess more acid sites than the conventional offretite due to their high crystallinity and hierarchical structure. The synthesized offretite is also more reactive than its conventional counterpart in the acylation of 2-methylfuran for biofuel production under non-microwave instant heating condition, giving 83.5% conversion with 100% selectivity to the desired product 2-acetyl-5-methylfuran. Hence, this amphiphile synthesis approach offers another cost-effective and alternative route for crystallizing zeolite materials that require expensive organic templates.