Influence of synthesis route on physico-chemical and catalytic properties of nanosized K-LTL zeolites

Abstract

Inorganic and organic routes were used to synthesize nanosized K-LTL zeolite. The role of synthesis route on the physico-chemical characteristics of synthesized materials was investigated using elemental analysis, powder x-ray diffraction, Raman spectral analysis, SEM, TEM, nitrogen-physisorption, MAS NMR and CO2-temperature programed desorption techniques. It was observed that K-LTL-org material composed of highly dispersed LTL nanocrystals, in contrast K-LTL-inorg sample showed highly agglomerated nanosized LTL particles because of high alkaline nature of Si, Al and K precursors used in the inorganic route. Additionally, material synthesized by organic route possessed large specific surface area with broad pore size (radius of 225 Å), and also high density of strong basic sites. Due to these properties, K-LTL-org sample showed superior performance in catalytic transesterification of glyceryl tributyrate compared to K-LTL -inorg sample. Also, the K-LTL-org catalyst showed excellent stability under applied reaction conditions and exhibited outstanding recyclability for (five cycles) without considerable loss of activity.