High activity of Ga-containing nanosponge MTW zeolites in acylation of p-xylene

Abstract

Abstract Aluminosilicate and gallosilicate MTW zeolites were prepared in the bulk and nanosponge form by direct hydrothermal synthesis. Designed materials were tested in acylation of p-xylene with benzoyl chloride and compared with large pore zeolite *BEA and medium pore zeolite MFI. Nanosponge MTW exhibited generally better performance than bulk MTW zeolites due to higher accessibility of the catalyst´s active sites in nanosponge zeolite. Selective transformation of benzoyl chloride towards target 2,5-dimethylbenzophenone was achievable over nanosponge MTW zeolites. The gallosilicate nanosponge MTW exhibited significantly higher conversion (61%) of benzoyl chloride than its aluminosilicate counterpart (27%) with the same concentration of Bronsted acid sites (0.04 mmol/g). This result is clearly caused by the suitable strength of acid centres in Ga-MTW, which enables the sufficient activation of BzCl molecules as well as efficient desorption of formed polar products. Additionally, the gallosilicate MTW outperformed both conventional zeolites *BEA and MFI used as reference materials.