Heteropolyacid Incorporated Bifunctional Core-Shell Catalysts for Dimethyl Ether Synthesis from Carbon Dioxide/Syngas

Doğu, Timur
Core-shell-type catalysts, which are synthesized by encapsulating the Cu-ZnO-Alumina type methanol synthesis catalyst (CZA) by silicotungstic acid (STA)-incorporated mesoporous alumina, were prepared following a hydrothermal route and tested in DME synthesis from syngas and CO2. Activity tests, which were performed in the pressure range of 30-50 bar, and the temperature range of 200-300 degrees C, with different feed compositions (CO2/CO/H-2: 50/-/50, 40/10/50, 25/25/50, 10/40/50) showed that the best-operating conditions for the highest DME yield were 275 degrees C and 50 bar. Results proved that the presence of CO2 in the syngas had a positive effect on the DME yield. The total conversion of CO + CO2 increased with an increase in CO2/CO ratio. An overall conversion of CO + CO2 and DME selectivity values were obtained as 65.6% and 73.2%, respectively, with a feed composition of H-2/CO2/CO = 50/40/10. Synthesis of methanol using the CZA catalyst from the CO2-containing gas mixtures was also investigated, and the total conversion of CO + CO2 and methanol selectivity values of 32.0% and 83.6%, respectively, were obtained with the H-2/CO2/CO = 50/40/10 gas mixture. Results proved that the new STA incorporated core-shell-type bifunctional catalysts were highly promising for the conversion of CO(2-)containing syngas to DME.


Dimethyl ether from syngas and effect of CO2 sorption on product distribution over a new bifunctional catalyst pair containing STA@SBA-15
Direct synthesis of dimethyl ether (DME) from syngas was investigated in the presence of a bifunctional catalyst pair containing silicotungstic acid (STA) incorporated SBA-15 (5, 10, 25% by wt. STA) for the in-situ dehydration of synthesized methanol. The methanol synthesis component of this catalyst mixture is a Cu/ZnO-based commercial (HF) catalytic material. The new STA@SBA-15 type solid acid catalysts synthesized in this study indicated ordered mesoporous structures with surface area values in the range...
Dimethyl Ether Synthesis over Novel Silicotungstic Acid Incorporated Nanostructured Catalysts
Ciftci, Aysegul; VARIŞLI, DİLEK; Doğu, Timur (2010-01-01)
Dimethyl ether (DME), which is an excellent green diesel-fuel alternate with excellent clean burning properties, is synthesized by dehydration of methanol over novel solid acid catalysts, which are synthesized following a direct hydrothermal route and using silicotungstic acid (STA) as the active compound. These mesoporous silicate structured catalysts have surface area values of 108-393 m(2)/g, depending upon their W/Si ratio. These catalysts showed very high methanol dehydration activity and also very hig...
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Doğu, Timur (2007-01-01)
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Enantioselective direct aldol reactions promoted by phosphine oxide aziridinyl phosphonate organocatalysts
Doğan, Özdemir (2015-12-15)
A series of phosphine oxide based chiral Lewis bases were screened as organocatalysts for silicon tetrachloride mediated direct asymmetric aldol reactions between cyclohexanone and various aromatic aldehydes. One of the phosphine oxide-aziridinyl phosphonate POAP-A Lewis bases formed the aldol products in up to 75% yield and with 65% ee.
Carbon-supported PT nanoparticles prepared by new surfactants and different reducing agents for methanol oxidation reaction
Kalyoncu, Sevda; Gökağaç Arslan, Gülsün; Department of Chemistry (2015)
In this thesis, carbon supported platinum catalysts were synthesized to investigate the effect of reducing agent and surfactant on the performance of catalyst towards methanol oxidation reaction. For this purpose, the catalysts were prepared by using PtCl4 as a starting material, propylamine (a) and dipropylamine (b) as surfactant, and sodium borohydride (catalyst I) and formaldehyde (catalyst II) as reducing agent. The prepared catalysts were characterized by X-ray diffraction (XRD), transmission electron ...
Citation Formats
B. PEKMEZCİ KARAMAN, N. OKTAR, and T. Doğu, “Heteropolyacid Incorporated Bifunctional Core-Shell Catalysts for Dimethyl Ether Synthesis from Carbon Dioxide/Syngas,” CATALYSTS, vol. 12, no. 10, pp. 0–0, 2022, Accessed: 00, 2022. [Online]. Available: https://hdl.handle.net/11511/101099.