Partial oxidation of ethanol on supported Rh catalysts: Effect of the oxide support

Tóth, Mariann; Varga, Erika; Oszkó, A.; Baán, Kornélia; Kiss, János; Erdöhelyi, András

doi:10.1016/j.molcata.2015.11.010

Cited by 37 publications

(18 citation statements)

References 65 publications

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“…Physisorbed carbon dioxide can be identified at 2337 cm −1 . The Rh-bonded linear carbon-monoxide resulted in a peak at 2100 cm −1 on partially oxidized Rh, whereas bridged CO appeared at 1924 cm −1 [66][67][68]. The peak at 2141 cm −1 represents the theoretical vibration energy of gas phase CO which is physisorbed on the surface like the carbon dioxide in our case.…”

Section: Photocatalytic Testsmentioning

confidence: 60%

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Photo-induced reactions in the CO 2 -methane system on titanate nanotubes modified with Au and Rh nanoparticles

László

Baán

Varga

et al. 2016

Applied Catalysis B: Environmental

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113

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The photocatalytic transformation of the methane-carbon dioxide system was investigated by in-situ methods in the present study. Titanate nanotube (TNT) supported gold and rhodium catalysts were used in the catalytic tests. Our main goal was the analysis of the role of the catalysts in the different parts of the reaction mechanism. The catalysts were characterized by X-ray photoelectron spectroscopy (XPS), high resolution transmission electron microscopy (HRTEM) and diffuse reflectance UV-vis spectroscopy (DR-UV-vis). Photocatalytic tests were performed in a continuous flow quartz reactor equipped with mass spectrometer detector and mercury-arc UV source. Diffuse reflectance infrared spectroscopy (DRIFTS) was used to analyze the surface of the catalyst during photoreaction. Post-catalytic tests were also carried out on the catalysts including XPS, temperature programmed reduction (TPR) and Raman spectroscopy methods in order to follow the changes of the materials. Titanate nanotube can stabilize even the smallest, molecular-like Au clusters which showed the highest activity in the reactions. Approximately 3% methane conversion was reached in the best cases while the carbon dioxide conversion was not traceable. It was revealed that water has a very important role in the oxidation reaction. The main discovered reaction routes are methane dehydrogenation and oxidation, the methyl coupling and the forming of structured carbon deposits on the catalyst surface. The source of the surplus CO can be mostly the reduction of carbon dioxide. During the reduction process photoelectrons and hydrogen ions brings about the CO 2 reduction via CO 2 • − radical anion.

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Section: Photocatalytic Testsmentioning

confidence: 60%

“…This band can be attributed to adsorbed formyl group [69] which forms in the reaction. Monodentate formate can be also identified from the bands at 1585 and 1384 cm −1 [66,70]. The absorption band of formyl is missing when metal is present.…”

Section: In-situ Infrared Spectroscopy Measurementsmentioning

confidence: 99%

Photo-induced reactions in the CO 2 -methane system on titanate nanotubes modified with Au and Rh nanoparticles

László

Baán

Varga

et al. 2016

Applied Catalysis B: Environmental

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113

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“…The appearance of the band as a shoulder at 1594 cm −1 may indicate that formate can also form during the adsorption of the reactants when Rh is not present [83,84]. This formate can act as an intermediate which easily transforms to carbonate and probably to methanol in the presence of water [85,86].…”

Section: In-situ Ftir Measurementsmentioning

confidence: 99%

Hydrogen evolution in the photocatalytic reaction between methane and water in the presence of CO2 on titanate and titania supported Rh and Au catalysts

et al. 2018

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The photocatalytic transformation of methane-water mixture over Rh and Au catalysts supported on protonated (H-form) titanate nanotube (TNT) was investigated. The role of the catalyst structure was analyzed using titania reference support. Furthermore the effect of carbon-dioxide addition was also investigated. The catalysts were characterized by high resolution transmission electron microscopy and X-ray photoelectron spectroscopy (XPS). Photocatalytic tests were performed with a mercury-arc UV source illuminating a continuous flow quartz reactor which was attached to a mass spectrometer. The surface of the catalysts was analyzed by diffuse reflectance infrared spectroscopy during the photoreactions. The changes of the catalysts due to photocatalytic usage were investigated by XPS and temperature programmed reduction methods as well. Most of the methane was generally transformed to hydrogen and ethane, and a small amount of methanol was also formed. The carbon dioxide addition enhanced the rate of the photocatalytic transformation of methane on Rh/TNT with increasing the lifetime of the electron-hole pairs. Bigger gold particles with mainly plasmonic character were more active in the reactions due to the photo induced activation of the adsorbed water. Surface carbon deposits were identified on the catalysts after the photoreactions. More oxidized carbon formed on the Au-containing catalysts than on the ones with Rh. Graphical AbstractKeywords Heterogeneous photocatalysis · Titanate nanotube · Gold nanoparticle · Molecular-like cluster · Surface plasmon resonance

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“…SBA-15 materials are being used mainly for other purposes different than the partial oxidation of ethanol. However, some works were published such as the research from Gayoung Lee 1 Unipetrol Centre for Research and Education / UNICRE, Areál Chempark, 436 70, Litvínov Záluží 1, Czech Republic et al [13] who used these type of materials for the oxidation of ethanol with the aim of producing hydrogen gas. Guoan Du et al [2] used vanadium grafted SBA-15 for the oxidation of methanol and Li et al [14] used Ni/SBA-15 for the steam reforming of ethanol.…”

Section: Introductionmentioning

confidence: 99%

Partial Oxidation of Ethanol Using VOx/SBA-15 and VOx/Fumed Silica Catalysts in a Bench-scale Stainless Steel Reactor

Herrador

Tišler

2017

Period. Polytech. Chem. Eng.

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Two VOx/SBA-15 catalysts and three VOx/SiO2-fumed silica, with 5, 10 and 1, 5, 10 %wt. vanadium content respectively, were tested in a stainless steel continuous flow reactor for the partial oxidation of ethanol. The catalysts were tested at 150 – 300 °C. Products were analyzed by GC-FID, GC-OFID and GC-MS. The aim was exploring the problematics which could be found when more industrial close conditions are used. The total conversion of ethanol and selectivity to acetaldehyde were different than the expected ones. For VOx/SiO2-fumed silica, the total conversion was higher with a lower selectivity to acetaldehyde compared to VOx/SBA-15 catalysts.

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Partial oxidation of ethanol on supported Rh catalysts: Effect of the oxide support

Cited by 37 publications

References 65 publications

Photo-induced reactions in the CO 2 -methane system on titanate nanotubes modified with Au and Rh nanoparticles

Photo-induced reactions in the CO 2 -methane system on titanate nanotubes modified with Au and Rh nanoparticles

Hydrogen evolution in the photocatalytic reaction between methane and water in the presence of CO2 on titanate and titania supported Rh and Au catalysts

Partial Oxidation of Ethanol Using VOx/SBA-15 and VOx/Fumed Silica Catalysts in a Bench-scale Stainless Steel Reactor

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