Synthesis of zeolite nanoreactors

• Main Author: Rajendran, Arvind
• Other Authors: School of Chemical and Biomedical Engineering
• Format: Research Report
• Language: English
• Published: 2012
• Subjects: DRNTU::Engineering::Nanotechnology
• Online Access: http://hdl.handle.net/10356/48025
• Institution: Nanyang Technological University

The aim of the project was to develop a novel procedure to prepare zeolite core-shell nanostructured materials and investigate their catalytic properties. The novelty of these materials is that the shell is made from zeolite materials while the core is made of a catalytic material. This type of materials represent intensification of two separate operations of separation and reaction on a single particle. They are expected to find key applications in catalysis, chemical sensors etc. Within the frame of this project, several novel structures were developed and the performance was evaluated. Of the several materials that were investigated two showed significant potential for further development. The first study involved the successful development of a continuous and c-oriented ZIF-69 membranes on porous -alumina substrates by an in situ solvothermal method. Single-gas permeation experiments through ZIF-69 membranes were carried out by a vacuum method at room temperature using H2, CH4, CO, CO2 and SF6, respectively. The permeances were in the order of H2 >CO2 >CH4 >CO>SF6. The separation of CO2/CO gas mixture was investigated by gas chromatograph (GC) and the permselectivity of CO2/CO was 3.5±0.1 with CO2 permeance of 3.6±0.3×10−8 molm−2 s−1 Pa−1 at room temperature. The second study dealt with the report the synthesis of micrometer-sized core-shell particles containing a catalyst core and a thin permselective zeolite shell and their application as a micromembrane reactor for the selective hydrogenation of the 1-hexene and 3,3-dimethyl-1-butene isomers. The bare catalyst, which was made from porous silica loaded with catalytically active nickel, showed no reactant selectivity between hexene isomers, but the core-shell particles showed high selectivities up to 300 for a 1-hexene conversion of 90%. Finally the potential of these materials for the selective adsorption of xylene isomers was also evaluated.