Synergy of Acidity and Morphology of Micro-/Mesoporous Materials in the Solid-Acid Alkylation of Toluene with 1-Decene

Abstract

Tuning the morphology of heterogeneous catalysts is of paramount importance for the design of efficient processes and requires detailed information on the physicochemical characteristics of the materials. Four micro-/mesoporous composites with different morphologies were synthesized by a dual-templating method using two-step crystallization with different zeolite seed concentrations. This work demonstrates the dependence of selectivity on the catalyst nature in solid-acid alkylation. It was demonstrated that a high concentration of weak acid sites leads to dialkyltoluene products, whereas a high concentration of strong acid sites is beneficial for other side reactions. It was shown that the morphology of catalysts played a crucial role in solid-acid alkylation. The alkylation mechanism defined in this study with different contributions of weak and strong acid sites could provide a route to the development of effective solid-acid catalysts.

Free Radical and Cationic Addition due to Clay Minerals Found in Bitumen Froth at 250 °C Probed with Use of α-Methylstyrene and 1-Octene

“…Reactions such as oligomerization, alkylation, and cracking compete with isomerization, and the reaction selectivity is said to depend on the reaction temperature and strength of acid sites on the catalyst surface. ,,,, For example, oligomerization is slow on weak acid sites and is favored at higher temperatures compared to isomerization reactions. , On the other hand, it was found in the literature that double bond migration could still occur on a higher number of weak acid sites. ,, …”

“…Friedel–Crafts-type alkylation reactions between olefins and aromatic compounds such as benzene and toluene in the presence of an acid catalyst are widely reported in the literature. − Such reactions have been reported to generate isomers of alkylated aromatics as well as polyalkylated aromatic compounds. ,, These alkylations are usually carried out in the presence of mineral acids such as H 2 SO 4 , HF, and H 3 PO 4 , Lewis acids such as AlCl 3 and BF 3 , or solid acids such as zeolites, clays, and sulfonic ion-exchange resins. ,, …”

Architectural design of core–shell nanotube systems based on aluminosilicate clay

“…43 Microporosity and structural variety could be beneficially broadened with silica-rich zeolite produced from halloysites with the ability to control the structural framework formation. 8,43–45…”

Mechanistic insights on Ru nanoparticle in situ formation during hydrodeoxygenation of lignin-derived substances to hydrocarbons

“…[39][40][41][42] Catalysts based on such materials with a high availability of acid sites allow including heavy substrates in the reaction, bypassing restrictions. 43,44 However, Ru catalytic systems based on porous materials have several limitations including high energy requirements for the preparation of catalysts, which is usually higher than that required for the HDO process. Harsh reduction conditions, necessity of environmentally polluting organic solvents, increase in cost owing to the use of expensive catalyst precursors involving multistep processes are among them.…”