Offretite Zeolite Single Crystals Synthesized by Amphiphile-Templating Approach.

Eng-Poh Ng,Fitri Khoerunnisa,Nur Hidayahni Ahmad,T Jean Daou,Tau Chuan Ling,Svetlana Mintova

doi:10.3390/molecules26082238

Abstract

Offretite zeolite synthesis in the presence of cetyltrimethylammonium bromide (CTABr) is reported. The offretite crystals were synthesized with a high crystallinity and hexagonal prismatic shape after only 72 h of hydrothermal treatment at 180 °C. The CTABr has dual-functions during the crystallization of offretite, viz. as structure-directing agent and as mesoporogen. The resulting offretite crystals, with a Si/Al ratio of 4.1, possess more acid sites than the conventional offretite due to their high crystallinity and hierarchical structure. The synthesized offretite is also more reactive than its conventional counterpart in the acylation of 2-methylfuran for biofuel production under non-microwave instant heating condition, giving 83.5% conversion with 100% selectivity to the desired product 2-acetyl-5-methylfuran. Hence, this amphiphile synthesis approach offers another cost-effective and alternative route for crystallizing zeolite materials that require expensive organic templates.

Highlights

Zeolites are crystalline microporous materials made up of tetrahedral TO4 (T = Si or Al) repeating units [1]
The synthesis of zeolites can be performed by using various techniques such as organo-templating [6,7]; organotemplate-free [8,9]; ionothermal [10,11]; interconversion [12,13]; assembly, disassembly, organization, and reassembly (ADOR) [14,15]; and fluoride routes [16,17]
Offretite zeolite with high crystallinity has been synthesized via the amphiphile-templating approach

Summary

Introduction

Zeolites are crystalline microporous materials made up of tetrahedral TO4 (T = Si or Al) repeating units [1]. These porous solids are widely used in catalysis, separation, and ion exchange processes due to their unique structure with defined size and shape [2,3,4]. Offretite zeolite (OFF topology) has a 3-dimensional channel system containing 12membered rings with a diameter 6.7 × 6.8 Å2. It is considered a very important zeolite due to its large pore size, which allows ease of molecular diffusion and accessibility [18]

Methods

Discussion

Conclusion