Zeolites and Zeotypes for Oil and Gas Conversion

Probing Zeolite Crystal Architecture and Structural Imperfections using Differently Sized Fluorescent Organic Probe Molecules

“…Factors contributing to this success are their excellent chemical and hydrothermal stability, well‐defined structure, and large surface area. Zeolites are traditionally used in major (petro‐)chemical processes, such as hydrocracking and catalytic cracking, as well as more recently in biomass conversion . Their widespread use motivates research into a proper understanding of the structure and behavior of these materials, as improvements have a large impact given the scale at which they are applied .…”

Probing Brønsted Acidity of Protonic Zeolites with Variable-Temperature Infrared Spectroscopy

“…The replacement of Al for Si in the tetrahedral units generates a net negative charge that has to be balanced by extraframework (exchangeable) cations or protons, as shown in Scheme 1; in the latter case, protonic zeolites, which show a distinctive Brønsted acidity, are generated. This acidity endows protonic zeolites with widespread applications (as solid acid catalysts) in a large range of chemical processes, which span the petrochemical industry, oil refining, methanol to olefin (MTO) conversion, and the production of fine chemicals, to name only a few examples [2][3][4][5][6][7][8]. The strength of their catalytic [Si(OH)Al] hydroxyl groups constitutes a main factor determining the catalytic activity and the se- lectivity of protonic zeolites; and, hence, the importance of having a reliable method to quantify relative acidity.…”

Electrophilic aromatic substitution over zeolites generates Wheland-type reaction intermediates

“…The reaction is proposed to involve the classical carbocationic σ-complex, which is better known as the Wheland intermediate, formed upon an attack by a π-electronrich aromatic on an electrophile 1 . Since its discovery by Friedel and Crafts in 1877, S E Ar has been extensively utilized by the chemical industry to produce functionalized aromatic compounds 2,3 . For example, ethylbenzene is currently produced by the ethylation of benzene (EB) with ethylene using a zeolite catalyst (for example, the Mobil-Badger process, Universal Oil Products' (UOP) EBOne process, Mobil-Raytheon's EBMax process and UOP/CEPSA process), and is a very important chemical intermediate in the petrochemical industry for the production of styrene [3][4][5][6][7] .…”

“…Since its discovery by Friedel and Crafts in 1877, S E Ar has been extensively utilized by the chemical industry to produce functionalized aromatic compounds 2,3 . For example, ethylbenzene is currently produced by the ethylation of benzene (EB) with ethylene using a zeolite catalyst (for example, the Mobil-Badger process, Universal Oil Products' (UOP) EBOne process, Mobil-Raytheon's EBMax process and UOP/CEPSA process), and is a very important chemical intermediate in the petrochemical industry for the production of styrene [3][4][5][6][7] . Currently, more than 99% of all ethylbenzene produced is used in the production of polystyrene-derived plastic materials 8 .…”

“…Traditionally, ethylbenzene is produced by homogeneous Friedel-Crafts-type Lewis acidic catalysts (for example, HF or AlCl 3 ), but disadvantages of this process include: corrosion, toxicity, waste disposal and halide impurities within aromatics [6][7][8] . In order to overcome these issues and achieve environmental tolerance and superior product selectivity through size control, zeolites (H-ZSM-5 and MCM-22) have been introduced by the petrochemical industry for the ethylene-mediated production of ethylbenzene, as they are heterogeneous catalysts that exhibit robust shape and size selectivity through regular micropores 6,[14][15][16] .…”