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583 results on '"Jongsomjit, Bunjerd"'

7. Influence of surface Sn species and hydrogen interactions on the OH group formation over spherical silica-supported tin oxide catalysts

Author

Boonpai, Sirawat, Wannakao, Sippakorn, Suriye, Kongkiat, Márquez, Victor, Panpranot, Joongjai, Jongsomjit, Bunjerd, Praserthdam, Piyasan, and Bell, Alexis T

Abstract

Silica-supported tin oxide catalysts are currently used in chemical processes involving hydrogen. A deeper understanding of the interactions of molecular hydrogen with the catalyst surface is crucial, to gain insights into structure-activity relationships that control the catalytic performance. This work aims to explore the influence of Sn species on silica-supported tin oxide catalysts and in particular the role of OH groups formed during hydrogen exposure. Tin oxide supported on spherical silica nanoparticle (SSP) catalysts was investigated using in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). The catalysts were synthesized using two different methods, incipient wetness impregnation (IWI-Sn) and incorporation (Inc-Sn) of Sn species to the SSP support with the sol-gel method. In situ DRIFTS showed that new OH groups on the silica surface are formed over SSP-supported tin oxide catalysts during the hydrogen exposure. The Sn-O-Si species play a key role in the formation of new OH groups on the silica surface over the catalysts. These Sn-O-Si species were predominant on the Inc-Sn catalysts, while the IWI-Sn catalyst presented various types of Sn species. Moreover, the Sn-O-Si species increased with the increase of Sn contents in both samples. The analytical results indicate that the newly generated OH groups appeared mostly on the silica surface surrounding the Sn-O-Si species. This journal is

Published
2020

29. Characteristics and catalytic properties of WO3supported on zeolite A-derived from fly ash of sugarcane bagasse via esterification of ethanol and lactic acid

Author

Tohdee, Kanogwan, Semmad, Surat, Nonthawong, Jirawadee, Praserthdam, Piyasan, Pungpo, Pornpan, and Jongsomjit, Bunjerd

Abstract

•A new low-cost biocatalyst for ethyl lactate production was examined.•WO3/zeolite-A shows a good thermal stability with only 3.91 % of weight loss.•Reusability performance of WO3/zeolite-A is preeminent over Amberlyst-15.•Deterioration of the catalyst surface was investigated.

Published
2024
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35. Bifunctional CaCO3/HY Catalyst in the Simultaneous Cracking-Deoxygenation of Palm Oil to Diesel-Range Hydrocarbons

Author

Febriansyar, Rosyad Adrian, Riyanto, Teguh, Istadi, I., Anggoro, Didi D., and Jongsomjit, Bunjerd

Subjects
General Computer Science, Space and Planetary Science, General Chemical Engineering, General Engineering, Geotechnical Engineering and Engineering Geology, Bifunctional, Biofuel, Calcium carbonate, Cracking, Deoxygenation, Palm oil
Abstract

Palm oil is a promising raw material for biofuel production using the simultaneous catalytic mechanism of the bifunctional cracking-deoxygenation reactions. Through the cracking-deoxygenation process, the chains of palmitic acid and oleic acid in the palm oil were converted to diesel-range hydrocarbons. The combination effects of CaCO3 and HY zeolite enhanced the bifunctional catalytic cracking-deoxygenation of palm oil into biofuel, because of the increasing acid and basic sites in the catalysts due to the synergistic roles of CaCO3 and HY. The introduction of CaCO3 on HY zeolite generated both a strong acid and strong basic sites simultaneously on the designed catalyst, which supports the bifunctional mechanisms of hybrid cracking-deoxygenation, respectively. The CaCO3 impregnated on the HY catalyst has a synergistic and bifunctional effect on the catalyst supporting cracking-deoxygenation reaction mechanisms as mentioned previously. The deoxygenation reaction required the bifunctional strong acid and strong basic sites on the CaCO3/HY catalyst through decarboxylation, decarbonylation, and hydrodeoxygenation reaction mechanisms. Meanwhile, the cracking reaction pathway was supported by the strong acid sites generated on the CaCO3/HY catalyst. In other words, the high acidity strength promotes diesel selectivity, whereas the high strength of basicity leads to the deoxygenation reaction.

Published
2022
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41. Bifunctional CaCO3/HY Catalyst in the Simultaneous Cracking-Deoxygenation of Palm Oil to Diesel-Range Hydrocarbons.

Author

Febriansyar, Rosyad Adrian, Riyanto, Teguh, Istadi, I., Anggoro, Didi D., and Jongsomjit, Bunjerd

Subjects
PALM oil, BIFUNCTIONAL catalysis, CALCIUM carbonate, HYDROCARBONS, DEOXYGENATION
Abstract

Palm oil is a promising raw material for biofuel production using the simultaneous catalytic mechanism of the bifunctional crackingdeoxygenation reactions. Through the cracking-deoxygenation process, the chains of palmitic acid and oleic acid in the palm oil were converted to diesel-range hydrocarbons. The combination effects of CaCO3 and HY zeolite enhanced the bifunctional catalytic crackingdeoxygenation of palm oil into biofuel, because of the increasing acid and basic sites in the catalysts due to the synergistic roles of CaCO3 and HY. The introduction of CaCO3 on HY zeolite generated both a strong acid and strong basic sites simultaneously on the designed catalyst, which supports the bifunctional mechanisms of hybrid cracking-deoxygenation, respectively. The CaCO3 impregnated on the HY catalyst has a synergistic and bifunctional effect on the catalyst supporting cracking-deoxygenation reaction mechanisms as mentioned previously. The deoxygenation reaction required the bifunctional strong acid and strong basic sites on the CaCO3/HY catalyst through decarboxylation, decarbonylation, and hydrodeoxygenation reaction mechanisms. Meanwhile, the cracking reaction pathway was supported by the strong acid sites generated on the CaCO3/HY catalyst. In other words, the high acidity strength promotes diesel selectivity, whereas the high strength of basicity leads to the deoxygenation reaction. [ABSTRACT FROM AUTHOR]

Published
2023
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49. The effect of different prepared TiCl4-MgCl2catalysts on the behavior of gas-phase ethylene/1-hexene copolymerization

Author

Pongchan, Thanyaporn, Tumawong, Praonapa, Phiwkliang, Wanna, Samingprai, Sutheerawat, Praserthdam, Piyasan, and Jongsomjit, Bunjerd

Abstract

•Different magnesium sources are used to prepare ZN catalysts.•Morphology and catalytic activity have been explored in gas-phase copolymerization.•Differences in characteristic of polymer are observed up on magnesium sources.•Mg(OEt)2based ZN catalyst exhibits good morphology and high catalytic activity.•The comonomer insertion of EH-ZN-MGE is the highest among other catalysts.

Published
2023
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