CO<sub>2</sub>atmosphere-enhanced methanol aromatization over the NiO-HZSM-5 catalyst

Li, Junhui; Hu, Chao; Tong, Kai; Xiang, Hao; Zhu, Zhirong; Hu, Zhonghua

doi:10.1039/c4ra06572g

Cited by 42 publications

(33 citation statements)

References 40 publications

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“…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.…”

Section: Resultsmentioning

confidence: 99%

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

Gong

Liu

et al. 2019

ChemCatChem

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Several Zn-modified HZSM-5 catalysts prepared by impregnation or ion exchange were characterized, and tested in methanol-to-aromatics (MTA) reaction. The obviously enhanced output of CO X by-products (CO & CO 2 ) was observed over these modified catalysts, although they showed the significantly improved selectivity of aromatics. It was found CO X formation is actually determined by the chemical state of surface Zn species. Concretely, both surface ZnO and surface metal-zinc are the reactive sites for the conversion of methanol to CO X and H 2 . At the initial period of reaction, surface ZnO (no reduction) causes CO X (mainly CO 2 ) formation may almost-exclusively through methanol steam-reforming. With the extending of reactiontime, while it's partially reduced to metal-zinc which more violently catalyzes the conversion of methanol to CO X (both CO and CO 2 ) may through the pathway of first dehydrogenationdecomposition and subsequent Water-Gas-Shift reaction. However, the surface ZnOH + species as Lewis acid hardly results in CO X formation, but significantly promotes aromatization due to its interaction-dehydrogenation effect. As high as possible ratio of the ZnOH + in surface Zn species is conducive to both suppressing the side-reaction which produces CO X and incubating the high aromatic selectivity even in the time-on-stream reaction. Our work may provide a theoretical guidance for developing the elegant catalyst for the MTA process with high carbon atom utilization.[a] Dr.

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Section: Resultsmentioning

confidence: 99%

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

Gong

Liu

et al. 2019

ChemCatChem

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“…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.…”

Section: Effect Of Preparation Methods On Catalytic Reactivitymentioning

confidence: 99%

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

Xia

et al. 2016

Catalysis Today

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“…The BET special surface area and total pore volume of SiO 2 both decreased slightly after hydrothermal treatment. From the physical properties of basic catalysts listed in Table 1, it could be seen that the BET surface area and the pore volume decreased greatly after modification with cesium carbonate, which indicated that Cs 2 CO 3 or Cs 2 O (as shown in Supporting Information) was not only loaded on the external surface but also impregnated into the pore of supports [22].…”

Section: Introductionmentioning

confidence: 99%

“…Figure 1b presents the XRD patterns of ZSM-5 with different SiO 2 -Al 2 O 3 and impregnated ZSM-5. It could be seen that no new diffraction peak appeared after modification, and both origin zeolite and Cs-loading zeolite had characteristic ZSM-5 diffraction peaks [22]. The catalysts were prepared with Cs 2 O-loading using cesium carbonate as the base precursor and calcined at 520°C or 600°C for 1 h. Few peaks of cesium carbonate or cesium oxide were observed in all modified catalysts.…”

Section: Introductionmentioning

confidence: 99%

Influence of Support Properties on the Activity of Basic Catalysts for Aldol Condensation of Formaldehyde and Methyl Acetate in a Continuous Flow Reactor

et al. 2015

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The aldol condensation of methyl acetate with formaldehyde to form methyl acrylate was studied in a continuous-flow reactor using a series of supported cesium basic catalysts with commercially available materials (ZSM-5, SiO 2 , and γ-Al 2 O 3 ) as carriers prepared by vacuum impregnation. The catalysts were characterized by N 2 adsorption-desorption, Fourier transform-infrared (FT-IR), X-ray diffraction (XRD), and temperature-programmed desorption of ammonia and carbon dioxide (NH 3 /CO 2 -TPD). The obtained results indicated that the selectivity of methyl acrylate was mainly influenced by the properties of supports. The formation of acetone is approximately proportional to the acidity of supports. The basicity of the catalysts was favorable to the formation of methyl acrylate according to the results of CO 2 -TPD. The hydrolysis of methyl acetate was inhibited over Cs-HT-SiO 2 prepared by SiO 2 after hydrothermal treatment. Furthermore, SiO 2 with the large mesoporous volume is superior to other supports, which shows the best catalytic activity for the aldol condensation reaction. On the other hand, the catalytic performance of zeolite basic catalysts was strongly influenced by the effect of reactant diffusion. Internal diffusion resulted in the increase of conversion of methyl acetate with increasing specific surface area, while the conversion of methyl acetate decreased with increasing the weight hourly space velocity (WHSV) due to the external diffusion.

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CO₂atmosphere-enhanced methanol aromatization over the NiO-HZSM-5 catalyst

Cited by 42 publications

References 40 publications

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

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

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

Influence of Support Properties on the Activity of Basic Catalysts for Aldol Condensation of Formaldehyde and Methyl Acetate in a Continuous Flow Reactor

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CO2atmosphere-enhanced methanol aromatization over the NiO-HZSM-5 catalyst

Cited by 42 publications

References 40 publications

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

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

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

Influence of Support Properties on the Activity of Basic Catalysts for Aldol Condensation of Formaldehyde and Methyl Acetate in a Continuous Flow Reactor

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CO₂atmosphere-enhanced methanol aromatization over the NiO-HZSM-5 catalyst

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

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