Recent Progress in Synthesis and Application of Nanosized and Hierarchical Mordenite-A Short Review

Zeolites with their unique properties find applications in various fields, including medicine, agronomy, ecology, production of detergents and drying agents, and in a number of industrial processes. Among zeolites, mordenite is particularly widespread because of its high silica/alumina ratio, which allows it to resist exposure to high temperatures and to acidic gases and liquids. Mordenite is commercially available as a natural mineral and as a synthesized material. This zeolite is mostly used in its synthetic form as an acid catalyst in the petrochemical industry for the isomerization of alkanes and aromatics. In this review, we consider the scientific literature on the structure, synthesis, and two main types of modifications that solve the diffusion difficulties during catalytic processes. The first type of modifications is related to a reduction of the size of the mordenite crystals obtained to submicron or nanometric range, whereas the second ones aim to obtain hierarchical mordenite samples by appropriate post-synthetic treatments. Both types of modifications find many other applications besides solving diffusion constraints in catalytic processes. Attempts to fine-tune and control the particle size in the first type of modifications or the pore size in the second ones by adjusting various parameters during the synthesis are described.