Microwave-assisted synthesis of mesostructured aluminosilicates (MA) for the preparation of nano-MoS2/MA catalysts active in decalin hydrocracking

Abstract

Aluminosilicates with disordered hexagonal mesostructure leading to wormhole-like porosity (MA, Si/Al = 50) were obtained using BEA-seeds and CTABr as directing agent of the hexagonal mesopores. A microwave-assisted synthesis was proposed as an alternative to the time-consuming conventional hydrothermal synthesis. Time of microwave irradiation was evaluated, and it was found that aluminosilicates were successfully synthesized in 5 min via microwave heating as compared to 2 days required in the conventional hydrothermal synthesis without sacrificing material properties. Mesoporous aluminosilicates with Si/Al molar ratio between 24 and 42 were obtained with a yield of about 95% and they were used as the acidic function in bifunctional MoS 2 /MA catalysts, where nano-MoS 2 was formed in-situ during the decalin hydrocracking. The acidic properties of the aluminosilicates, specifically, number and strength of Brønsted acid sites have an impact on the catalytic activity of the bifunctional catalysts measured for decalin hydroconversion, leading mostly skeletal isomerization and single-ring opening products. • Mesostructured aluminosilicates with different Si/Al were obtained by microwave-assisted hydrothermal synthesis in 5 min. • Mesoporous aluminosilicates were successfully used as acidic function in bifunctional catalyst for decalin hydrocracking. • Bifunctional MoS 2 -MA catalysts were obtained in-situ during decalin hydrocracking. • Decalin conversion was influenced by the number and the strength of the Brønsted acid sites.