SYNTHESIS OF MFI ZEOLITE USING GREEN STRUCTURE- DIRECTING AGENT BASED ON AMMONIUM DIOXOLANE COMPOUND

• Main Author: Yanitasari Hidayat, Dyah
• Format: Theses
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/34279
• Institution: Institut Teknologi Bandung

Zeolite is an aluminosilicate material which has widely used as a heterogenous catalyst. Synthesis of high silica zeolites usually involve the use of organic molecules as structure directing agent (SDA). After the zeolite formed, the organic molecules in pore of the zeolite framework should be removed by calcination. The calcination process can cause organic molecules to be destroyed and formed CO2 and NOx that are not environmentally friendly. One method that can be done to deal with the removal of organic molecules by calcination method is to use an organic molecule that can be easily decomposed within the zeolite pores. The use of organic molecules that are easily decomposed can eliminate high temperature treatment for SDA removal and more environmentally friendly. Here, we reported the use of ammonium dioxolane cation compound that can be decomposed into carbonyl and diol fragments, hence removing the compounds easily in the zeolite structure after functioned as SDA. This newly-type of dioxolane compound was synthesized in two-steps starting from the reaction between glycerol and acetone to form dioxolane group. In the next step, bromination and nucleophilic substitution was carried out to obtain ammonium dioxolane compound. The compound shows the formation of ammonium dioxolane salt after an evaluation from the infrared, solution-state 1H NMR, solution-state 13C NMR and mass spectroscopy. The SDA is mixed in the aluminosilicate gel under molar composition of Si/Al = 17.86, KOH/Si = 0.238 and SDA/Si = 0.033 and hydrothermally treated at 175°C for 6 days. Eventually, the crystallization leads to the formation MFI zeolite. In the absence of SDA, the aluminosilicate gel treated under similar conditions resulted in BEA zeolite. The SDA was fragmented inside the zeolite pore by treating in acidic solution using 1M HCl at 80°C and the cation fragment was removed by ion exchange method. XRD patterns show that SDA can be successfully removed without destructing the zeolite framework.