Disproportionation of toluene over HZSM-5 zeolites

Disproportionation of Toluene on Monoliths Washcoated with Metal Oxide Modified ZSM5

“…The desorption profile for ZSM5 exhibits two peaks at 450 and 841 K and a broad shoulder at 590 K. The peaks appearing at 450 and 841 K can be assigned to the desorption of ammonia from the weak and strong acid sites, respectively, and the broad shoulder to the desorption from acid sites of medium strength. This is in agreement with the results of Meshram et al [21] who reported the presence of three types of acid sites (weak, medium and strong) on ZSM5. Compared to the ZSM5 zeolite, there was a reduction in the desorption peak areas and hence, the total number of acid sites in all the modified ZSM5 catalysts.…”

High Performance Ni Based Catalyst for Toluene Hydrocracking

“…The toluene conversion by the acid zeolite alone is less than 50%, with a product distribution that corresponds to the disproportionation of toluene to give C6's (includes benzene) and xylenes. Similar results have been reported previously for H-ZSM-5 at temperatures above 400°C [25][26][27][28].…”

Selectivity Enhancement to the Exclusive Formation of Ethyltoluenes and Hydrogen During Dehydroalkylation of Toluene with Ethane

“…At a contact time of 0.12 h, no aromatic side products can be detected any more. Although small deviations from unity of the S benzene /S xylenes ratio may be expected and explained for example by dealkylation of xylenes [26], the total absence of xylenes at low contact times strongly suggests that other reaction mechanisms also account for benzene formation. We therefore suggest that, under conditions of high contact time, benzene is formed along with xylenes mainly from the disproportionation of toluene.…”