Studies on acidity and activity of kaolin-supported Ag-doped HZSM–5 in methanol to olefins process

Abstract

Effect of addition of kaolin of concentration of 15, 25, and 50 wt% and incorporation of silver (1 wt %) to HZSM–5 zeolite on its acidity and catalytic activity in the methanol to olefins process has been thoroughly investigated. Furthermore, these catalysts were characterized by chemisorptions of ammonia, temperature-programmed desorptions of ammonia, FTIR analysis, and surface area measurement. Kaolin significantly reduced the acidity of HZSM–5 zeolite. During the calcinations, a solid-ion transaction involving protons of the zeolite and cations of the clay occurs. The neutralization of several zeolite acid-sites reduced methanol conversion in HZSM–5 zeolite. The highest conversion of methanol to olefins, on the other hand, was discovered. The incorporation of silver into the catalyst imparts dehydrogenation activity, and therefore, paraffins, the end products of the methanol conversion on zeolite, have been changed to olefins, resulting in better selectivity towards lower olefins. Finally, cost-effective, template-free efficient silver-doped kaolin-supported HZSM–5 catalysts were prepared. © 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.