Ethanol adsorption and oxidation on bimetallic catalysts containing platinum and base metal oxide supported on MCM-41

Rintramee, Kamolwan; Föttinger, Karin; Rupprechter, Günther; Wittayakun, Jatuporn

doi:10.1016/j.apcatb.2011.11.050

Cited by 51 publications

(38 citation statements)

References 43 publications

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“…The increasing in intensity and broadening of the band at 1590 cm -1 (at 250 o C) also indicates the formation of carbonate species. 53 Co and Co-Mn-modified systems were more reactive than the Mn ferrospinel. 60 The DRIFT spectra obtained on Mn 0.6 Fe 2.4 O 4 (Fig 6-D), also exhibit the bands for acetate species, formed by the reaction of ethoxy species with surface oxygen (1598, 1555, 1433 and 1334 cm -1 ).…”

Section: Surface Characterization: Drift Spectroscopymentioning

confidence: 92%

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Towards an improved process for hydrogen production: the chemical-loop reforming of ethanol

Vozniuk

Agnoli²,

Artiglia³

et al. 2016

Green Chem.

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International audienceM-modified ferrospinels with the formula M0.6Fe2.4Oy (M = Co, Mn or Co/Mn) were employed as ionic oxygen and electron carrier materials for an alternative sustainable route to produce hydrogen via chemical-loop reforming of ethanol. The new materials were tested in terms of both redox properties and catalytic activity to generate hydrogen by oxidation with steam, after a reductive step carried out with ethanol. In addition, the research includes in situ DRIFTS and in situ XPS studies that allowed the extraction of information at the molecular level and following surface changes within the reduction/re-oxidation processes during ethanol chemical-loop reforming. It was found that Co(II)-incorporation in spinels effectively improves decomposition/oxidation of ethanol, however a greater amount of coke is accumulated. On the other hand, addition of Mn(II) into the system helps to significantly reduce the amount of coke and hence to avoid fast deactivation of the material. Thus, the behavior of Co0.3Mn0.3Fe2.4Oy was shown to be the most promising one, as this material forms less coke during the reduction step, and consequently less COx is generated during the re-oxidation step with water, nevertheless a high hydrogen yield is maintained

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Section: Surface Characterization: Drift Spectroscopymentioning

confidence: 92%

“…[50][51][52][53][54] However, the species formed with increasing temperatures are more related to the surface chemistry of each compound. According to the literature, ethanol adsorbs on the surface mainly as an ethoxide, formed from the scission of the O-H bond.…”

Section: Surface Characterization: Drift Spectroscopymentioning

confidence: 99%

Towards an improved process for hydrogen production: the chemical-loop reforming of ethanol

Vozniuk

Agnoli²,

Artiglia³

et al. 2016

Green Chem.

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“…62 The broad band in the wavenumber region of 3000−3650 cm −1 and the peak at 1633 cm −1 are ascribed to OH stretching and OH bending, respectively. 63 For the sample dispersed in ethanol and deposited on silicon substrate (red curve), we observe two evident signals at 2845 and 2923 cm −1 related to CH stretching, 63,64 while OH related features seem to be not relevant. For comparison, we can consider the FT-IR spectrum of TiO 2 nanoparticles in ethanol solvent (see Fig.…”

Section: Infrared and Photoluminescence Analysismentioning

confidence: 92%

Wet Environment Effects for Ethanol and Water Adsorption on Anatase TiO₂ (101) Surfaces

et al. 2019

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Titanium dioxide exhibits superior photocatalytic properties, mainly occurring in liquid environments through molecular adsorptions and dissociations at the solid/liquid interface. The presence of these wet environments is often neglected when performing ab initio calculations for the interaction between the adsorbed molecules and the TiO 2 1 surface. In this study we consider two solvents, i.e. water and ethanol, and show that the proper inclusion of the wet environment in the methodological scheme is fundamental for obtaining reliable results. Our calculations are based on structure predictions at a density functional theory level for molecules interacting with the perfect and defective anatase (1 0 1) surface under both vacuum and wet conditions. A soft-sphere implicit solvation model is used to describe the polar character of the two solvents. As a result, we find that surface oxygen vacancies become energetically favorable with respect to subsurface vacancies at the solid/liquid interface. This aspect is confirmed by ab initio molecular dynamics simulations with explicit water molecules. Ethanol molecules are able to strongly passivate these vacancies, whereas water molecules only weakly interact with the (1 0 1) surface, allowing the coexistence of surface vacancy defects and adsorbed species. Infrared and photoluminescence spectra of anatase nanoparticles exposing predominantly (1 0 1) surfaces dispersed in water and ethanol support the predicted molecular-surface interactions, validating the whole computational paradigm. The combined analysis allows for a better interpretation of TiO 2 processes in wet environments based on improved computational models with implicit solvation features.

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“…Rintramee et al. observed the formation of ethane in ethanol temperature‐programmed desorption (TPD) profiles of a Pt catalyst at high temperatures and proposed the hydrogenation of ethylene to form ethane from ethanol 11. Ochoa et al.…”

Section: Formation Of Alkanes From the Corresponding Alcohols Over Vamentioning

confidence: 99%

Reduced Vanadium and Molybdenum Oxides Catalyze the Equivalent Formation of Ethane and Acetaldehyde from Ethanol

2014

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Catalytic tests for ethanol conversion were performed on vanadium and molybdenum oxides with different oxidation states. We found for the first time that equivalent amounts of ethane and acetaldehyde were formed catalytically over V 2 O 3 and MoO 2 . No influence of the reaction temperature was observed on the selectivity to ethane and acetaldehyde in the range of 533-653 K over V 2 O 3 and MoO 2 . The reactions of methanol, 1-propanol, and 2-propanol also produced the corresponding alkanes and aldehydes in a 1:1 ratio. A reaction scheme for the formation of ethane and acetaldehyde from ethanol is proposed in which a hydrogen transfer reaction occurs between two ethanol molecules adsorbed on the adjacent metal cation-oxygen anion pair sites to form ethane, acetaldehyde, and water in one step.Vanadium and molybdenum oxide catalysts have attracted much attention because of their unique catalytic properties and commercial application in various chemical processes. These catalysts are known to be active as oxidation and acid catalysts in reactions such as the partial oxidation of alkanes [1] and dehydration of alcohols. [2] In reports on the reaction of alcohols over vanadium and molybdenum oxide catalysts, the catalytic reaction was performed in the presence of oxygen and aldehydes, and carboxylic acid and CO 2 were produced. However, we found that ethane was formed from ethanol conversion over vanadium and molybdenum oxides under N 2 . The formation of alkanes from the corresponding alcohols is not normally a feature of the dehydration and dehydrogenation of alcohols. There is no report that describes the formation of alkanes from alcohols over reduced vanadium or molybdenum oxides. However, several reports describe the formation of alkanes from the corresponding alcohols, which are summarized in Table 1.McMonagle and Moffat proposed that the formation of ethane from ethanol over 12 molybdophosphates proceeds through the secondary hydrogenation of ethylene formed by the dehydration of ethanol because the selectivity to ethane increased in the presence of H 2 and the selectivity to acetaldehyde was always higher than that of ethane. In this study, Mo 6+ in the catalyst was reduced to Mo 5+ during the reaction.The selectivities to ethane and acetaldehyde decreased and the selectivity to ethylene increased over the reduced catalyst because of the loss of active sites for the dehydrogenation of ethanol. [3] Other reports also show the relationship between the selectivities to alkanes and aldehydes and the catalytic oxidation states. Abu-Zied and El-Awad showed that the formation of ethane from ethanol over Cd-Cr-O catalysts proceeded through the hydrogenation of ethylene produced by the dehydration of ethanol. As the selectivity to ethane increased with an increase in the selectivity to acetaldehyde and Cr is known to form hydride species, CrÀH was proposed as the active species in the hydrogenation of alcohols over Cr. In this reaction, Cr was reduced from Cr 6+ to Cr 3+ during the catalysis because of the absence of ...

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Ethanol adsorption and oxidation on bimetallic catalysts containing platinum and base metal oxide supported on MCM-41

Cited by 51 publications

References 43 publications

Towards an improved process for hydrogen production: the chemical-loop reforming of ethanol

Towards an improved process for hydrogen production: the chemical-loop reforming of ethanol

Wet Environment Effects for Ethanol and Water Adsorption on Anatase TiO₂ (101) Surfaces

Reduced Vanadium and Molybdenum Oxides Catalyze the Equivalent Formation of Ethane and Acetaldehyde from Ethanol

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Ethanol adsorption and oxidation on bimetallic catalysts containing platinum and base metal oxide supported on MCM-41

Cited by 51 publications

References 43 publications

Towards an improved process for hydrogen production: the chemical-loop reforming of ethanol

Towards an improved process for hydrogen production: the chemical-loop reforming of ethanol

Wet Environment Effects for Ethanol and Water Adsorption on Anatase TiO2 (101) Surfaces

Reduced Vanadium and Molybdenum Oxides Catalyze the Equivalent Formation of Ethane and Acetaldehyde from Ethanol

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Wet Environment Effects for Ethanol and Water Adsorption on Anatase TiO₂ (101) Surfaces