| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 66499 | Journal of Molecular Catalysis A: Chemical | 2011 | 16 Pages |
In order to increase the yield of cymene in alkylation of toluene with isopropanol, ZSM-5 zeolite units were incorporated into a mesostructured material. The catalysts were characterized by X-ray diffraction, TGA, SEM, NH3 temperature-programmed desorption and FTIR of pyridine adsorption. XRD analysis indicated that a structurally well ordered cubic MCM-48 aluminosilicate was successfully assembled from ZSM-5 zeolite seeds. The ZSM-5/MCM-48 catalyst exhibited significantly improved toluene conversion and yield of cymene product for toluene isopropylation. Catalytic tests show that the ZSM-5/MCM-48 composite material exhibits high catalytic activity compared with the conventional Y-zeolite for catalytic cracking of 1,3,5-triisopropylbenzene (TIPB). The exceptional catalytic performance of ZSM-5/MCM-48 catalyst in cracking and alkylation reaction was attributed to the easier access of active sites provided by the mesopores for both reactant and larger product molecules. The apparent activation energies for the cracking of 1,3,5-TIPB over ZSM-5/MCM-48 catalyst were found to decrease as follows: EC/CM-3 (tertiary cracking) > EC/CM-4 (disproportionation) > EC/CM-2 (secondary cracking) > EC/CM-1 (primary cracking).
Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (167 K)Download as PowerPoint slideHighlights► Mesopores containing ZSM-5 is reported for alkylation and cracking reactions. ► Presence of mesopores led to a high 1,3,5-TIPB conversion. ► Acidity as well as pore size of catalysts plays a crucial role in the cracking reaction.
