Enhancement in activity and shape selectivity of zeolite BEA by phosphate treatment for 2-methoxynaphthalene acylation

Abstract

Pore-engineering of large pores of zeolite BEA by phosphate treatment effectively narrowed the pores with the creation of new acid sites. Phosphate modification of BEA with lower loading was more effective in pore modification without affecting the zeolite structure. Pyrophosphates and polyphosphates are mainly responsible for the narrowing of the zeolite pores. Both the activity and shape selectivity for 2-acetyl-6-methoxynaphthalene were enhanced in the acylation of 2-methoxynaphthalene. At higher concentration of phosphates, conversion and selectivity decreased due to dealumination. 1% P loading was found to be optimum for the acylation of 2-methoxynaphthalene. With the optimized phosphate modification of BEA, high selectivity of 78% to 2-acetyl-6-methoxynaphthalene was achieved with 77% conversion.