Ultrasonic Synthesis of Al-SBA-15 Nanoporous Catalyst for t-Butylation of Ethylbenzene

Abstract

Mesoporous Al-SBA-15 ( $\text{Si}/\text{Al}=25$ ) catalysts were synthesised by the ultrasonic (US) irradiation method at different time durations (1, 3, and 5 h) using the pluronic P123 triblock copolymer as a template. The synthesised catalysts were examined in detail by XRD, ICP-AES, N2 adsorption-desorption, SEM, TEM, FT-IR, and TGA characterization techniques. The characterization results reveal that the catalysts possess a well-ordered hexagonal mesoporous structure. The catalytic activity of synthesised materials was investigated in the tert-butylation of ethylbenzene at different reaction conditions, and their identified products are para-tert-butylethylbenzene (p-tert-BEB) and meta-tert-butylethylbenzene (m-tert-BEB). It was found that high ethylbenzene conversion (69%) is achieved at 200°C with high selectivity towards p-tert-butylethylbenzene (80%). The optimum feed ratio (ethylbenzene: t-butyl alcohol) was 1 : 2, and the feed rate was 2 ml/h for high conversion and product selectivity. All these synthesised Al-SBA-15 (US) catalysts are compared with hydrothermally synthesised Al-SBA-15 (HT) at the same reaction conditions.