The deactivation mechanism of two typical shape-selective HZSM-5 catalysts for alkylation of toluene with methanol

Production of bio‐based p‐xylene via catalytic pyrolysis of biomass over metal oxide‐modified HZSM‐5 zeolites

“…Those authors suggested that the improvement of p ‐xylene selectivity was mainly attributed to the partial blockage of pore openings of ZSM‐5 zeolite by Ga‐oxides . However, it has been proven that the alkylation of toluene or benzene with methanol can produce xylenes including p ‐xylene when using zeolite as a catalyst . This work found that more p ‐xylene was formed in the the co‐catalytic pyrolysis of sawdust and methanol.…”

“…17 However, it has been proven that the alkylation of toluene or benzene with methanol can produce xylenes including p-xylene when using zeolite as a catalyst. 36,39,40 This work found that more p-xylene was formed in the the co-catalytic pyrolysis of sawdust and methanol. The improvement of xylenes yield in the co-feed process can be explained by the fact that methanol produces methyls, and then benzene and toluene formed from catalytic pyrolysis of sawdust are alkylated to xylenes.…”

Insight into the Formation of COX By‐Products in Methanol‐to‐Aromatics Reaction over Zn/HZSM‐5: Significantly Affected by the Chemical State of Surface Zn Species

“…Chen and Niu et al attributed this high binding energy peak to ZnOH + species, [31,33] which is Zn-Lewis (ZnÀ L) acid site formed from the strong interaction of the zinc species with Brønsted (B) acid sites. [5,35,36] Because for Zn(IE)/ZSM-5, the relatively larger-size ZnOH + species may uniformly locates on both internal and external surface and then this reduce the accessibility of micropore and surface (internal/ external). The majority of zinc species is present as ZnOH + species (91.6 %) for Zn(IE)/ ZSM-5, while that was much lower for Zn(IM)/ZSM-5.…”

“…This suggests that the structure of HZSM-5 was not changed and no new phase was produced during modification. [35,36] The results of ICP for the parent and modified HZSM-5 are shown in Table 1. As can be seen, AÀ Zn(IM)/HZSM-5 and Zn(IE)/ HZSM-5 showed the very close content of Zn element, about 0.8 wt%.…”

Hydrocracking of the crude oil from thermal pyrolysis of municipal wastes over bi-functional Mo–Ni catalyst

“…In the conventional impregnation method for preparing the supported metal oxide catalysts [44][45][46][47], the Al 2 O 3 support impregnated with the aqueous solution of Ni(NO 3 ) 2 was dried at 393 K, and calcinated at 773 K to produce NiO/Al 2 O 3 (NiO was reduced to Ni in hydrogen before hydrocracking tests). Usually, the metal oxides in the form of small particles were obtained on the support.…”