Effect of zinc salt on the synthesis of ZSM-5 for alkylation of benzene with ethanol

Study of the alkylation of benzene with methanol for the selective formation of toluene and xylene over Co3O4–La2O3/ZSM-5

“…Niwa et al 22 found that moderate hydrothermal treatment changed the B acid strength, and the number of acid sites decreased with increasing water vapor partial pressure, although the acid strength increased. Gao et al 23 observed that zinc salt had a great effect on ZSM-5 synthesis; the lower the SiO 2 /ZnO ratio of the gel, the higher the Lewis/Brönsted ratio. Chandawar et al 24 modied ZSM-5 with P or B to eliminate the strong acid sites on the surface and achieve higher ethylbenzene selectivity.…”

Tailoring hierarchical zeolite composites with two distinct frameworks for fine-tuning the product distribution in benzene alkylation with ethanol

“…41,54,55 Ethylbenzene (EB) is a crucial feedstock for the production of styrene, which is one of the most important industrial monomers for plastics and textiles. 56,57 Currently, ethylbenzene is mainly produced by the alkylation of benzene with ethylene or ethanol over acidic zeolite-based catalysts. 5,58,59 The use of ethanol instead of ethylene suppresses coke formation, leading to a longer catalyst lifetime, and also benets in terms of the economic signicance due to a lower cost of biomass derived ethanol.…”

“…5,58,59 The use of ethanol instead of ethylene suppresses coke formation, leading to a longer catalyst lifetime, and also benets in terms of the economic signicance due to a lower cost of biomass derived ethanol. 57,60 However, there are several side products obtained from the alkylation process including toluene, xylene, and higher aromatics (C 9 + ) formed by secondary reactions on the acidic sites. Therefore, the modication of the acidic properties of the catalyst surface is of crucial importance in tuning the product selectivity in benzene alkylation.…”

“…For example, with a crystal size in the nanoscale, a larger inter-crystalline void space is provided, resulting in higher pore volume, and more accessible acidic sites, all of which lead to higher activity, lower coke content, and improved stability. 17,57,62 Therefore, to modify a zeolite combined with small crystals and a reasonable acidity, the fabrication of the core-shell structure of the mordenite core with nanocrystalline ZSM-5 would be advantageous. To the best of our knowledge, although the potential applications of modied catalysts in alkylation have been demonstrated, the catalytic performance of core-shell mordenite@ZSM-5 composite has not been evaluated in benzene alkylation.…”

Hafnium-Doped Mesoporous Silica as Efficient Lewis Acidic Catalyst for Friedel–Crafts Alkylation Reactions

“…To overcome these disadvantages, there are increasing interests of using heterogeneous acids as catalysts, together with the use of alcohol [7] or ester [8] as alkylating reagent, which make the FC reaction more environmentally benign and cost-efficient. During the past few years, several types of Bronsted- and Lewis-type solid catalysts have been identified with good reactivities in FC alkylation reaction, including supported heteropolyacid (HPA) [9], supported metal salts [10], zeolites [11], and mesoporous solid acid catalysts [12]. For example, Lingaiah et al [13] reported tin-exchanged heteropoly tungstate was successfully applied to the benzylation of arenes with benzyl alcohol and almost full conversion and quantitative products were obtained at 393 K of reaction temperature.…”