Nafion-Incorporated Silicate Structured Nanocomposite Mesoporous Catalysts for Dimethyl Ether Synthesis

Being chemically and thermally stable, Nation resin is considered to be an attractive solid acid catalyst. Although it has high acid strength and the ability to catalyze a wide range of reactions, the catalytic activity of Nation is limited, because of its very low specific surface area. In this study, mesoporous Nafion-silica nanocomposites were developed by following a one-pot acidic hydrothermal synthesis procedure. Synthesized catalysts were determined to have well-dispersed structures with high surface area values (595-792 m(2)/g) and strong Bronsted, as well as Lewis, acid sites. The activities of these novel catalysts were tested in dimethyl ether synthesis from methanol in a flow system. The effects of modifications in the synthesis procedure and Nafion loading showed that the material synthesized from a solution containing a Nafion/silica weight ratio of 0.15 and refluxed with a 2 M sulfuric acid-ethanol (SAE) mixture for surfactant removal was the best catalyst for this reaction. Production of the green transportation fuel alternate dimethyl ether (DME) was achieved with this catalyst at very high yields with almost 100% DME selectivity at >180 degrees C.


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...
Vanadium incorporated high surface area MCM-41 catalysts
Gucbilmez, Y; Doğu, Timur; Balci, S (Elsevier BV, 2005-02-28)
High surface area MCM-41 (1452 m(2)/g) and V-MCM-41 materials were synthesized by a direct hydrothermal synthesis method. Characteristic XRD patterns, SEM and AFM photographs indicated no significant change in the morphology of MCM-41 by incorporation of vanadium. XPS and EDS results proved that incorporation of vanadium into the MCM-41 structure was successfully achieved when vanadyl sulfate hydrate was used as the vanadium source. However, use of ammonium vanadate as the vanadium source was not equally su...
Iridium(O) nanoparticles dispersed in zeolite framework: A highly active and long-lived green nanocatalyst for-the hydrogenation of neat aromatics at room temperature
TONBUL, YALÇIN; Zahmakıran, Mehmet; Özkar, Saim (Elsevier BV, 2014-04-27)
The complete hydrogenation of aromatic molecules is one of the key transformation employed in the synthetic and petroleum chemistry. Described herein is a new catalytic nanomaterial for the hydrogenation of neat aromatics under mild conditions. A novel nanocatalyst, consisting of iridium(O) nanoparticles stabilized by zeolite with EAU framework could reproducibly been prepared from the reduction of iridium(III)-exchanged zeolite in an aqueous sodium borohydride solution at room temperature and characterized...
Guluronic acid content as a factor affecting turbidity removal potential of alginate
Moral, Cigdem Kivilcimdan; Ertesvag, Helga; Sanin, Faika Dilek (2016-11-01)
Alginates are natural polymers composed of mannuronic and guluronic acid residues. They are currently extracted from brown algae; however, alginate can also be synthesized by some species of Azotobacter and Pseudomonas. Alginates with different proportion of mannuronic and guluronic acids are known to have different characteristics and form gels at different extents in the presence of calcium ions. The aim of this work was to investigate the usefulness of alginate as a non-toxic coagulant used in purificati...
Activated carbon-tungstophosphoric acid catalysts for the synthesis of tert-amyl ethyl ether (TAEE)
Obali, Zeynep; Doğu, Timur (2008-05-01)
Catalytic activities of bulk tungstophosphoric acid (HPW) and its supported forms on activated carbon were investigated in the vapor phase etherification reaction of isoamylene with ethanol in a continuous flow reactor. Tungstophosphoric acid (H3PW12O40 center dot 11H(2)O) was supported on activated carbon having a surface area of 796 m(2)/g, at two different loading levels (25% and 31%) by aqueous impregnation technique and the kinetic experiments were done in a temperature range between 353 and 370 K. Sup...
Citation Formats
A. Ciftci, N. A. Sezgi, and T. Doğu, “Nafion-Incorporated Silicate Structured Nanocomposite Mesoporous Catalysts for Dimethyl Ether Synthesis,” INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH, pp. 6753–6762, 2010, Accessed: 00, 2020. [Online]. Available: