Treatment of boron-containing pentasil-type zeolites under ‘boron-extracting’ conditions

Abstract

Thermal or hydrothermal treatments of boron-containing pentasil-type zeolites, as well as acid-leaching procedures, lead to the partial or full removal of the framework boron atoms from the material. Resulting from this removal, the boron-stimulated lattice contraction is nearly completely cancelled. Catalytic properties of the ‘deborated’ material in acid-catalysed reactions are very close to those measured on comparable boron-free samples. This fact can be utilized in the production of template-free ZSM-5 of enhanced SiO₂/Al₂O₃ molar ratio.