Selective production of propylene from methanol over high-silica mesoporous ZSM-5 zeolites treated with NaOH and NaOH/tetrapropylammonium hydroxide

Ahmadpour, Javad; Taghizadeh, Majid

doi:10.1016/j.crci.2015.05.002

Cited by 81 publications

(63 citation statements)

References 59 publications

(115 reference statements)

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“…The alkali‐treated materials pre‐MZS0.2 and pre‐MZS0.6 have lower Si/Al ratios and higher Al contents than commZS (Table ). These results are consistent with the occurrence of desilication, in which alkaline conditions favour the hydrolysis/dissolution of framework Si species over framework Al species . The Si/Al ratio followed the order commZS (12)>pre‐MZS0.2 (10)>pre‐MZS0.6 (6), which suggests that more alkaline conditions led to more extensive desilication.…”

Section: Resultssupporting

confidence: 86%

“…Based on a literature survey, zeolites with Si/Al ratios in the range 25–50 are typically used as starting materials for the introduction of mesoporosity through desilication processes by using alkaline conditions . The reason for this is partly that ZSM‐5 materials with relatively low Si/Al ratios tend to be more resistant towards desilication because the [AlO 4 − ] groups may protect the neighbouring silicon atoms against OH − attack . However, with adequate desilication conditions, it is possible to introduce mesoporosity into MFI zeolites within a broad range of Si/Al ratios (approximately 12–200) .…”

Section: Resultssupporting

confidence: 82%

“…The powder X‐ray diffraction (PXRD) patterns of commZS and the corresponding modified versions show the reflections characteristic of the MFI topology; no other crystalline phases were formed (Figure ) . Hence, the structural integrity of commZS was fairly well preserved.…”

Section: Resultsmentioning

confidence: 99%

See 2 more Smart Citations

MFI Acid Catalysts with Different Crystal Sizes and Porosity for the Conversion of Furanic Compounds in Alcohol Media

et al. 2017

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Solid acid catalysts possessing MFI topology and different crystal sizes and porosities were explored for the conversion of carbohydrate‐biomass‐derived α‐angelica lactone and 5‐(hydroxymethyl)furfural, in 1‐butanol at T=120–170 °C, to give levulinate esters and furanic ethers. Micro/mesoporous microcrystalline catalysts were prepared by post‐synthesis base/acid treatments of ZSM‐5 zeolite; the influence of the desilication (base) conditions on the material properties was investigated. A nanocrystalline ZSM‐5 sample was synthesised by using hydrothermal, dynamic conditions and used as a reference material. A comparison of the catalytic performances of materials featuring different morphological, textural, and acid properties highlights a complex interplay between the acid and textural properties. The best‐performing catalyst (MZS0.6) was obtained by post‐synthesis‐treatment; fairly good catalytic stability was confirmed by catalyst recycling, contact tests, and characterisation of the spent catalyst. MZS0.6 was compared with the macrorecticular ion‐exchange resin Amberlyst‐15, chosen as a benchmark solid acid catalyst, in the two reaction systems.

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Section: Resultssupporting

confidence: 86%

Section: Resultssupporting

confidence: 82%

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MFI Acid Catalysts with Different Crystal Sizes and Porosity for the Conversion of Furanic Compounds in Alcohol Media

et al. 2017

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“…Apart from N 2 adsorption, low angle XRD and SEM analyses, the generation of mesoporosity is also directly supported by ICP‐OES results. Si/Al ratio decreases after alkali treatment (Table ) due to desilication in SAPO‐5 and SAPO‐34 material resulting in additional porosity …”

Section: Resultsmentioning

confidence: 99%

“…The intrinsic properties of materials can be tailored by surface modification; for example, the acidity of BEA zeolite can be controlled using alkali ion‐exchange treatment, and after modification it showed improved catalytic activity in the production of isobutylene from acetone . Moreover, hierarchical SAPO‐5, SAPO‐34, ZSM‐5, ZSM‐48, MCM‐22, Zn‐SAPO‐34, and H‐β zeolite type of materials were prepared using different alkali treatment through post‐synthesis route and their catalytic performance was found to be better than that of as made zeolites . Verboekend et al reported synthesis of hierarchical silicoaluminophosphate by using different acid and base treatments and their catalytic application in model alkylation reaction of benzyl alcohol with toluene .…”

Section: Introductionmentioning

confidence: 99%

Synthesis of Hierarchical SAPO‐5 & SAPO‐34 Materials by Post‐Synthetic Alkali Treatment and Their Enhanced Catalytic Activity in Transesterification

Jadav

Bandyopadhyay

2020

Eur J Inorg Chem

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SAPO‐5 and SAPO‐34 materials were modified using post‐synthetic alkali treatment, which results in the formation of hierarchical SAPO‐5 and SAPO‐34 materials. To test the generation of mesoporosity, the modified materials were thoroughly characterized using XRD, FE‐SEM, TGA, ICP‐OES, and N2 adsorption/desorption techniques. Alkali treated SAPO‐5 and SAPO‐34 materials were utilized for the model reaction triacetin transesterification, under optimized conditions by varying the catalyst amount and reaction time: 90 % triacetin conversion with 66 % methyl acetate yield was achieved using modified SAPO‐5 catalyst, whereas 68 % triacetin conversion with 37 % methyl acetate yield was achieved using modified SAPO‐34 catalyst. The alkali treated SAPO‐5 catalyst was stable up to the 4th cycle.

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Structural Effects of HZSM‐5 Zeolite on Methanol‐to‐Propylene Reaction

et al. 2020

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ZSM‐5 zeolite was synthesized using n‐butylamine as a template under hydrothermal conditions. The morphology of the prepared zeolites was changed with the initial gel composition. The influences of OH−/template and H2O/template ratios on the morphology, mesoporosity, acid properties, and crystal size of the synthesized zeolites were evaluated, also the structural effects of the prepared zeolites on the catalytic performances of the methanol‐to‐propylene process. Increasing the external surface area and mesopore volume of the catalysts improved the propylene selectivity. A direct relationship between the deactivation of catalysts and their acidic properties was found. The results were derived from laboratory data and need to be re‐examined on a larger scale to ensure their accuracy on an industrial scale.

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Selective production of propylene from methanol over high-silica mesoporous ZSM-5 zeolites treated with NaOH and NaOH/tetrapropylammonium hydroxide

Cited by 81 publications

References 59 publications

MFI Acid Catalysts with Different Crystal Sizes and Porosity for the Conversion of Furanic Compounds in Alcohol Media

MFI Acid Catalysts with Different Crystal Sizes and Porosity for the Conversion of Furanic Compounds in Alcohol Media

Synthesis of Hierarchical SAPO‐5 & SAPO‐34 Materials by Post‐Synthetic Alkali Treatment and Their Enhanced Catalytic Activity in Transesterification

Structural Effects of HZSM‐5 Zeolite on Methanol‐to‐Propylene Reaction

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