Modifying the acidity of H-MOR and its catalytic carbonylation of dimethyl ether

Wang, Meixia; Huang, Shouying; Lü, Jing; Cheng, Zaizhe; Liu, Ying; Wang, Shengping; Ma, Xinbin

doi:10.1016/s1872-2067(16)62484-1

Cited by 70 publications

(64 citation statements)

References 40 publications

(51 reference statements)

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“…Nitrogen adsorption–desorption isotherms of Al-RUB-41 zeolites with different Si/Al ratios are compared in SI Figure S3a. All curves display a type I isotherm, the dramatic increase of N 2 adsorption amount at low relative pressure owes to the microporous structure of zeolite . No obvious hysteresis loop between the adsorption and desorption branches at the relative pressure range from 0.4 to 0.95 illustrates that there almost exist no mesopores.…”

Section: Resultsmentioning

confidence: 90%

“…All curves display a type I isotherm, the dramatic increase of N 2 adsorption amount at low relative pressure owes to the microporous structure of zeolite. 28 No obvious hysteresis loop between the adsorption and desorption branches at the relative pressure range from 0.4 to 0.95 illustrates that there almost exist no mesopores. Pore size distributions of these samples in the micropore region (0.2 to 2.0 nm) and mesopore region (3 to 35 nm) are displayed in SI Figure S3b,c.…”

Section: Resultsmentioning

confidence: 99%

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A Carbonylation Zeolite with Specific Nanosheet Structure for Efficient Catalysis

Yao

Fan

et al. 2021

ACS Nano

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Up to now, the member of zeolite family has expanded to more than 230. However, only little part of them have been reported as catalysts used in reactions. Discovering potential zeolites for reactions is significantly important, especially in industrial applications. A carbonylation zeolite catalyst Al-RUB-41 has special morphology and channel orientation. The 8-MR channel of Al-RUB-41 is just perpendicular to its thin sheet, making a very short mass-transfer distance along 8-MR. This specific nature endows Al-RUB-41 with efficient catalytic ability to dimethyl ether carbonylation reaction with beyond 95% methyl acetate selectivity. Compared with the most widely accepted carbonylation zeolite catalysts, Al-RUB-41 behaves a much better catalytic stability than H-MOR and a greatly enhanced catalytic activity than H-ZSM-35. A space-confined deactivation mechanism over Al-RUB-41 is proposed. By erasing the acid sites on outer surface, Al-RUB-41@SiO2 catalyst achieves a long-time and high-efficiency activity without any deactivation trend.

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Section: Resultsmentioning

confidence: 90%

Section: Resultsmentioning

confidence: 99%

A Carbonylation Zeolite with Specific Nanosheet Structure for Efficient Catalysis

Yao

Fan

et al. 2021

ACS Nano

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“…The amounts of weak, moderate, and strong acid sites are listed in Table 3. According to the work of Ma and coworkers [20,32], strong acid sites can be considered as framework Brønsted acid sites in MOR because the high-temperature peak disappears when the Brønsted acid sites are replaced by sodium. The appearance of a moderatetemperature peak is accompanied by a sharp decrease in the low-temperature peak, suggesting that the addition of Ag led to a variation in the distribution of the acid sites.…”

Section: Acid Site Distributionmentioning

confidence: 99%

“…Therefore, adjusting and controlling the distribution of Brønsted acid sites is of great significance in improving the reactivity of MOR. Wang et al [20] successfully improved the distribution of acid sites in 8-MR by changing the molar ratio of Si/Al and adding template agents. Xue et al [21] used steam treatment for the selective dealumination of MOR, reducing the amount of acid sites in 12-MR. Zhao et al [22] formed more Brønsted acid sites in the MOR through steam treatment and improved the reaction activity.…”

Section: Introductionmentioning

confidence: 99%

Silver-Modified Nano Mordenite for Carbonylation of Dimethyl Ether

Qian

et al. 2021

Catalysts

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Mordenite (H-MOR) catalysts were synthesized by a hydrothermal method, and silver-modified mordenite (Ag-MOR) catalysts were prepared by ion exchange with AgNO3 at different concentrations. The performance of these catalysts in the carbonylation of dimethyl ether (DME) to methyl acetate (MA) was also evaluated. The catalysts were characterized by Ar adsorption/desorption, XRD, ICP-AES, SEM, HRTEM, 27Al NMR, H2-TPR, NH3-TPD, Py-IR, and CO-TPD. According to the characterization results, Ag ion exchange sites were mainly located in the 8-membered ring (8-MR) channels of Ag-MOR; evenly dispersed Ag2O particles were also present. The acid site distribution was changed by the modification of Ag, and the amount of Brønsted acid sites increased in 8-MR and decreased in 12-MR. The CO adsorption performance of the catalyst significantly increased with the modification of Ag. These changes improved the conversion and selectivity of the carbonylation of DME. Over 4Ag-MOR in particular, DME conversion and MA selectivity reached 94% and 100%, respectively.

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“…The desorption peak below 600 K (peak α) was attributed to NH3 desorbed from NH4 + •nNH3 associations [45] or weak acid sites [46]. The peak above 600 K (peak β) was attributed to NH3 desorption from strong acid sites [47], among which the sites located at the 8-MR side pockets were active in DME carbonylation [33]. Table 2 presents the quantitative analysis results of strong acid sites in the catalysts.…”

Section: Acidic Properties Of the H-mor Catalystsmentioning

confidence: 99%

Spacial hindrance induced recovery of over-poisoned active acid sites in pyridine-modified H-mordenite for dimethyl ether carbonylation

Zhao

Tian

Zhang

et al. 2019

Chinese Journal of Catalysis

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Modifying the acidity of H-MOR and its catalytic carbonylation of dimethyl ether

Cited by 70 publications

References 40 publications

A Carbonylation Zeolite with Specific Nanosheet Structure for Efficient Catalysis

A Carbonylation Zeolite with Specific Nanosheet Structure for Efficient Catalysis

Silver-Modified Nano Mordenite for Carbonylation of Dimethyl Ether

Spacial hindrance induced recovery of over-poisoned active acid sites in pyridine-modified H-mordenite for dimethyl ether carbonylation

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