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Seo, Gon; Kim, Na-Hyeon; Lee, Younghee; Kim, Jong-Ho

doi:10.1023/a:1019028522765

Cited by 32 publications

(6 citation statements)

References 17 publications

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“… 12 , 13 Also, materials with ordered mesoporous pore structures such as MCM-41 and KIT-1 have been investigated. 14 However, as for the catalysts mentioned above, either their selectivities are not high or their stabilities are poor. Compared with most amorphous and mesoporous catalysts, zeolite can trigger the skeletal isomerization reaction of 1-butene to isobutene at a lower reaction temperature.…”

Section: Introductionmentioning

confidence: 98%

“…Houžvička et al and Gao and Moffat prepared catalysts possessing isomerization activities by loading phosphoric acid and 12-tungstophosphoric acid onto silica, respectively. In addition, halogen-modified alumina catalysts can also induce the skeletal isomerization reaction of 1-butene. , Also, materials with ordered mesoporous pore structures such as MCM-41 and KIT-1 have been investigated . However, as for the catalysts mentioned above, either their selectivities are not high or their stabilities are poor.…”

Section: Introductionmentioning

confidence: 99%

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Improved Catalytic Performances of the NaOH-Treated ZSM-22 Zeolite in the 1-Butene Skeletal Isomerization Reaction: Effect of External Acid Sites

Wang

Bao

et al. 2023

ACS Omega

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In this paper, a series of alkaline-treated ZSM-22 zeolite samples were prepared by treating the parent ZSM-22 zeolite using NaOH aqueous solution with different concentrations. By investigating the effects of alkaline treatment on the parent ZSM-22 zeolite, we discovered that the alkaline treatment contributed to the reduction of Brønsted acid sites due to the coverage of extra-framework Al on its external surface. In addition, it was found that the alkaline-treated samples were favorable to the improvement of the isobutene yield and selectivity, while these features appeared to be low for the subsequent acid-washed counterparts in the skeletal isomerization reaction of 1-butene. These results indicate that the catalytic performance of ZSM-22 zeolite is related to reduced amounts of Brønsted acid sites in it. To further reveal the reasons for the promoted catalytic performances of the alkaline-treated ZSM-22 series zeolites, we studied the properties of coke deposited on the two series of samples using Raman spectroscopy and thermogravimetric analysis and mass spectrometry (TG/MS-TPO). It was shown that the carbon deposited on the alkaline-treated series samples was mainly distributed at the outer surface, while the coke was distributed to a relatively lesser extent at the exterior surface for the acid-washed series samples. Moreover, by partially passivating outer acid sites of the parent zeolite, the selected alkaline-treated zeolite, and acid-washed zeolite, their isobutene selectivities were all improved with the decrease in outer acid sites. These phenomena confirmed that the improved catalytic performances of the alkaline-treated samples are related to their decreased external Brønsted acid site density, which further demonstrated that the high isobutene yield and selectivity in the skeletal isomerization reaction of 1-butene is realized via the monomolecular reaction pathway of 1-butene.

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Section: Introductionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

Improved Catalytic Performances of the NaOH-Treated ZSM-22 Zeolite in the 1-Butene Skeletal Isomerization Reaction: Effect of External Acid Sites

Wang

Bao

et al. 2023

ACS Omega

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“…The presence and type of acid sites, their acid strength, the density and their distribution have been evaluated to understand the catalytic performance of ferrierite in the butene isomerization reaction [3]. The characteristic behavior of this zeolite is a high conversion with low isobutene selectivity at a short time-on-stream, being it associated with the presence of strong acid sites [4].…”

Section: Introductionmentioning

confidence: 99%

Linear butene skeletal isomerization over boron-promoted ferrierite

et al. 2008

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“…However, it inevitably induces defects on the wafer surface, including those triggered by microscratches caused by poor dispersion of ceria particles and insufficient repulsive forces between the abrasives and film surface. [3][4][5] These defects can induce a leakage current or a short between gates. 6 Therefore, defects on the wafer surface are a crucial issue in the STI CMP process.…”

mentioning

confidence: 99%

Increase in the Adsorption Density of Anionic Molecules on Ceria for Defect-Free STI CMP

Kim

Park

et al. 2010

J. Electrochem. Soc.

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We have investigated the adsorption density of anionic molecules on a ceria surface and its effect on suppressing defects on the SiO 2 films during shallow trench isolation ͑STI͒ chemical mechanical planarization ͑CMP͒. Intermolecular vacancies in poly͑methyl methacrylate͒ ͑PMMA͒ caused by ionic repulsive forces between its carboxyl groups provide adsorption sites on the ceria surface for 3-hydroxypentanedioic acid-3-carboxylic acid ͑hydrogen citrate͒, which has a molecular length of 8.39 Å. This allows for an increase in adsorption density. The coadsorption of PMMA and hydrogen citrate on the ceria surface leads to an increase in negative charge at the ceria particle-water interface and provides repulsive forces between the ceria particle and the SiO 2 surface. Ceria slurry prepared with the coadsorption of PMMA and hydrogen citrate shows a suppression of remaining particles ͑90.9%͒ and microscratches ͑100%͒ on the SiO 2 film, resulting from a decrease in the adhesion force of ceria particles on the SiO 2 film. This effect was analyzed by force measurement using atomic force microscopy.

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Cited by 32 publications

References 17 publications

Improved Catalytic Performances of the NaOH-Treated ZSM-22 Zeolite in the 1-Butene Skeletal Isomerization Reaction: Effect of External Acid Sites

Improved Catalytic Performances of the NaOH-Treated ZSM-22 Zeolite in the 1-Butene Skeletal Isomerization Reaction: Effect of External Acid Sites

Linear butene skeletal isomerization over boron-promoted ferrierite

Increase in the Adsorption Density of Anionic Molecules on Ceria for Defect-Free STI CMP

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