PhD defence: Binder Effects in Catalyst Extrudates

Zeolite-based catalysts have many applications in the (petro-)chemical industry and these catalysts are often used in large, meters-high reactors. Zeolites are often a fine powder and if a large reactor is filled with this fine powder, it is difficult to get a gas or fluid through the reactor. For this reason, zeolites are often mixed with different materials, like binder materials, to form macroscopic catalyst extrudates. A binder material can have a large influence on the properties of the catalyst extrudate and therefore can have a large effect on the performance of the catalyst extrudate.

In this PhD thesis, we have studied the influence of an Al2O3 or SiO2 binder on zeolite H-ZSM-5-containing catalyst extrudates during three different industrially important chemical reactions; namely the oligomerization of 1-hexene, the transalkylation of toluene with 1,2,4-trimethylbenzene and the disproportionation of toluene. We have employed a combination of characterization techniques, like UV-vis micro-spectroscopy and confocal fluorescence microscopy and we build an operando setup to analyze the products during reaction with gas chromatography.

The results presented in this PhD thesis show that for all three chemical reactions the choice of binder material has a significant influence on the catalyst activity and selectivity. By comparing the results for different chemical reactions, we can see which binder effects are similar for the different reactions, and which binder effects are very reaction specific. The results show that is vital to get a better understanding of binder effects in industrial catalysis.