An Environmentally Friendly Catalyst for Aromatic Hydrocarbons Alkylations with 1-alkenes

Abstract

Nowadays, the alkylation of aromatic compounds using 1-alkenes is still conducted in industrial applications using Friedel-Crafts alkylations. The most commonly used catalysts are aluminum chloride (AlCl3) and hydrofluoric acid (HF), both of which pose significant environmental concerns. An alternative approach involves the use of solid acid catalysts, specifically zeolites, which may offer a more environmentally acceptable option. In this study, the alkylation of toluene with 1-decene was performed in a batch reactor under autogenous pressure in the liquid phase at a temperature of 100 °C. Zeolite Y samples with varying sodium content (molar ratio of Si/Al approximately equal to 2.27), were employed as the parent catalysts. These zeolites underwent a dealumination process followed by the removal of residual sodium and the cationic form of aluminum via ion exchange with ammonium nitrate. Accessible physical and chemical methods were used for the characterisation of the prepared catalyst. The residues of sodium were found to influence the catalytic activity in the alkylation reaction. The formation of a secondary mesoporous structure enhanced the selectivity towards the production of 2-decyltoluene. Following the dealumination and ion exchange treatment, an increased ratio of Brønsted to Lewis acid sites was observed, resulting in the suppression of dimerization reactions in the alkylation products.