Microporous and Mesoporous Materials for Catalytic Applications

The Special Issue “Microporous and Mesoporous Materials for Catalytic Applications has twelve peer-reviewed articles (Contributions 1–12), out of which there are eight research papers (Contributions 1–8) and four review papers (Contributions 9–12). The main research topics of the published peer review articles are synthesis and physico-chemical characterizations of structured acidic and metal-modified microporous and mesoporous materials. The prepared acidic, transition, and noble metal-modified microporous and mesoporous materials have been utilized in the production of fuel components such as gasoline, diesel, and jet fuels, pharmaceuticals, fine chemicals, and specialty and medicinal drug molecules. Catalytic reaction mechanism, kinetic studies, and deactivation of catalysts have been reported for these applications. Furthermore, reactions of immense interest for academic and industrial researchers have been studied in the published research papers. These important reactions are methanol to aromatics on hybrid zeolite catalysts (Contribution 1), synthesis of CBO (CO₃O₄/Bi₂O₃) degradation of fipronil and acetochlor pesticides in aqueous medium (Contribution 2), hydrodesulfurization of thiophene in an n-heptane stream (Contribution 3), dimethyl ether to olefins (Contribution 4), catalytic distillation of atmospheric residue of petroleum (Contribution 5), effect of basic production on porous supported alumina for production of acetins (Contribution 6), Ni and Ce grafted mesoporous silica KIT-6 for adsorption of CO₂ (Contribution 7), Ordered mesoporous nZVI/Zr-Ce-SBA-15 catalysts used for nitrate reduction (Contribution 8), a comprehensive review of production of fine chemicals (Contribution 9), porous aerogel structures as promising matrials for photocatalysis (Contribution 10), Hierarchical zeolite by alkaline treatment (Contribution 11) and catalytic ozonation of textile waste water (Contribution 12).

The synthesis of aluminosilicate microporous and ordered mesoporous materials using hydrothermal synthesis has been the focus of research in these published research papers. Preparation of transition and noble metal-modified microporous and mesoporous materials has been carried out using evaporation impregnation, ion-exchange, deposition precipitation, co-precipitation, chemical vapor deposition, and in situ synthesis methods. It is noteworthy to mention that authors in the published peer-reviewed research papers have also utilized novel synthesis methods, such as the introduction of transition and noble metals during the hydrothermal synthesis and post-synthesis bi-metallic modifications.

In-depth physico-chemical characterizations of the as-synthesized pristine and metal-modified microporous and mesoporous materials have been performed using characterization methods such as X-ray powder diffraction for determination of the structural features and phase purity and scanning electron microscopy for the measurements of the crystal morphology, shape, and size distributions (Contributions 1,3,4). The amounts, strengths, and types of Brønsted and Lewis acid sites have been analyzed by FT-IR equipment using pyridine as a probe molecule. The authors of some research papers have also carried out measurements of the amounts of Brønsted and Lewis acid sites and total acidity using temperature-programmed desorption of ammonia (Contributions 3,5,6). Furthermore, the characterization of basic sites in pristine and metal-modified has been carried out using temperature-programmed desorption of CO₂. Transmission electron microscopy and high-resolution transmission electron microscopy have been applied for the determination of the size and dispersion of noble and transition metals (Contributions 2,3,5). The oxidation states of metal nanoparticles have been measured using X-ray photoelectron spectroscopy. The chemical compositions of the synthesized acidic and metal-modified microporous and mesoporous materials have been measured using energy dispersive X-ray microanalyses and inductively coupled plasma spectroscopy (Contributions 9,11,12). Surface area, pore volume, and pore size distributions have been measured using nitrogen physisorption (Contributions 9–10).

The novel research results published in the research papers of the Special Issue titled “Microporous and Mesoporous Materials for Catalytic Applications” will enhance the scientific knowledge in the research fields of the synthesis, characterization, and applications of these industrially important catalytic materials for the development of green process technology and environmentally friendly industrial processes for the production of renewable energy, green fuels, and chemicals. Furthermore, the published research papers and reviews will contribute to the understanding of the fundamental, theoretical, and practical aspects of reaction mechanisms, adsorption phenomena, shape selectivity, diffusion of reactants and products, catalyst deactivation, and regenerations.