Catalytic synergy between the low Si/Al ratio Zn/ZSM-5 and high Si/Al ratio HZSM-5 for high-performance methanol conversion to aromatics

Fu, Tingjun; Shao, Juan; Li, Zhong

doi:10.1016/j.apcatb.2021.120098

Cited by 69 publications

(41 citation statements)

References 57 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Especially for HZSM-5 with a low Si/Al ratio, the aromatization could more likely occur on its strong acid sites and the aromatics could be produced with high selectivity [13]. While increasing the Si/Al ratio of HZSM-5 could reduce the density of acid sites, so that the selectivity of light alkenes was increased [14,15]. Long F. Lin et al [11] also concluded that, for the catalytic cracking of 1-pentene to propylene, the main reaction pathways and the molar ratio of propylene to ethene were controlled by acid strength.…”

Section: Introductionmentioning

confidence: 99%

Relationship between Acidity and Activity on Propane Conversion over Metal-Modified HZSM-5 Catalysts

Zhou

Zhang

et al. 2021

Catalysts

View full text Add to dashboard Cite

A systematic study of the comparative performances of different metal-impregnated HZSM-5 catalysts (Zn, Ga, Mo, Co, and Zr) for propane conversion is presented. The physicochemical properties of catalysts were characterized by means of XRD, BET, SEM, TEM, FTIR, XPS, 27Al MAS NMR, NH3-TPD and Py-FTIR. It was found that the acidities of the catalysts were significantly influenced by loading metal. More specifically, Mo-, Co- or Zr-modified catalysts showed a large metal size and low acidic density, resulting high olefin selectivity, while Zn- or Ga-modified catalysts maintained their small metal size and acidic density, and mainly reduced B/L due to the Lewis acid sites created by Zn or Ga species, resulting in high aromatics selectivity. Experimental results also showed that there is a balance between metals size and medium and strong acidity on propane conversion. Moreover, based on the different acidity of metal-modified HZSM-5 catalysts, the mechanism of propane conversion was also discussed.

show abstract

Section: Introductionmentioning

confidence: 99%

Relationship between Acidity and Activity on Propane Conversion over Metal-Modified HZSM-5 Catalysts

Zhou

Zhang

et al. 2021

Catalysts

View full text Add to dashboard Cite

show abstract

“…The nanosized HZSM-5 zeolite (with a silica to alumina ratio of 16) purchased from Nankai University Catalyst Plant, China was chosen as the initial catalyst. The zinc-modified HZSM-5 zeolites were prepared by the traditional incipient wetness impregnation method with Zn(NO 3 ) 2 solution, 45 and the desired zinc contents were 1, 2, 3, 4, and 5 wt %. After the Zn(NO 3 ) 2 solutions were added to the initial zeolite, the prepared samples were aged for 6 h at ambient temperature, followed by drying at 120 °C overnight.…”

Section: ■ Experimental Sectionmentioning

confidence: 99%

Optimizing the Acid Properties of the HZSM-5 Catalyst for Increasing the p-Xylene Yield in 1-Hexene Aromatization

Gao

Zhi

Cao

et al. 2022

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

For increasing p-xylene (PX) yield in 1-hexene aromatization, the effect of the acid properties of HZSM-5 on the distribution of aromatics and the selectivity of PX in the aromatics with a carbon number of 8 (A8) were investigated in this work. The results showed that the aromatics yield and the proportion of A8 in aromatics increased and then decreased when increasing the L/B, reaching the maximum values when L/B was 2.9 (44.2 and 37.9 wt %). When decreasing the external surface Brønsted acid sites (EBA) by chemical liquid deposition (CLD), the aromatics are first increased and then decreased but the selectivity of PX in A8 (PX selectivity) constantly increased. Zn3Si0.75/ Z5 with an EBA proportion of 8.6% showed a higher PX selectivity (58.9 vs 24.2%) while maintaining a high aromatics yield (50.5 vs 44.2 wt %), suggesting the existence of a suitable L/B and EBA proportion for the production of PX.

show abstract

“…It can be seen that the commercial Z20 and Z113 zeolites have typical MFI structures. 16,29,30 All samples have excellent crystallinities. This suggested that the structure of the zeolite was not destroyed during the modification process.…”

Section: Introductionmentioning

confidence: 99%

“…It has been reported that high acid site density accelerates coke deposition, which further leads to catalyst deactivation. 16,34,48 It is well known that B acid sites are important sites of isomerization reactions, 19,49 and L acid sites are the main sites of carbon deposition. 8 Compared with 3La/ Z113, 1Z20/3Z113 catalysts have more B and L acid sites.…”

Section: Introductionmentioning

confidence: 99%

Novel Composite Catalysts Efficiently Catalyze C8 Aromatics by Controlling the Reaction Pathway

Miao

Wang

Zhao

et al. 2022

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

Pt-3Si/Z20 and 3La/Z113 catalysts were prepared by modifying high Si/Al ratio ZSM-5 and low Si/Al ratio ZSM-5, respectively. Here, a high-performance composite catalyst was prepared by combining two catalysts (Pt-3Si/Z20 and 3La/Z113) with different functions. Many techniques were performed to characterize the catalysts. The composite catalyst has multiple active sites with different functions by integrating the properties of the two catalysts. The efficient synergistic effects of dealkylation and isomerization are applied to the complex C8 aromatics reaction. The reaction pathways of ethylbenzene, m-xylene, and o-xylene in C8 aromatics were successfully controlled. Additionally, we found that the different spatial arrangements of the two catalysts had effects on the xylene losses of the catalysts. This could be attributed to the disproportionation of p-xylene during the reaction. At 360 °C, EB conversion, PX yield, and xylene loss were 71.6%, 23.2%, and 1.75%, respectively. This work has important guiding significance for the industrial production of p-xylene.

show abstract

Catalytic synergy between the low Si/Al ratio Zn/ZSM-5 and high Si/Al ratio HZSM-5 for high-performance methanol conversion to aromatics

Cited by 69 publications

References 57 publications

Relationship between Acidity and Activity on Propane Conversion over Metal-Modified HZSM-5 Catalysts

Relationship between Acidity and Activity on Propane Conversion over Metal-Modified HZSM-5 Catalysts

Optimizing the Acid Properties of the HZSM-5 Catalyst for Increasing the p-Xylene Yield in 1-Hexene Aromatization

Novel Composite Catalysts Efficiently Catalyze C8 Aromatics by Controlling the Reaction Pathway

Contact Info

Product

Resources

About