Reactions of Carboxylic Acids on Oxides

Pestman, Robert; Koster, R.M.; Duijne, A. van; Pieterse, J.A.Z.; Ponec, V.

doi:10.1006/jcat.1997.1624

Cited by 170 publications

(151 citation statements)

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“…21 This effect would be consistent with the proposed mechanism because water would hydrolyze the carboxylate bonds and carbon dioxide would competitively bind metal sites either in the bulk or on the surface. The proposed mechanism is somewhat similar to that of Pestman et al 4 in that a proton is initially removed from the α-carbon on the molecule whose carboxylate group will eventually form carbon dioxide; however, the reaction sequence in Figure 13 would also alleviate concerns that Nagashima et al 18 expressed about the model by Pestman et al because the mechanism has the C−C cleavage occurring in the same step as ketone production, thereby prohibiting formation of side product, such as methanol. It is worth noting that the proposed reaction sequence could potentially be generalized to any type of metal oxide ketonization catalyst as well as to being able to occur on the surface or throughout the bulk of the respective material.…”

Section: Acs Catalysissupporting

confidence: 82%

Insights into the Ceria-Catalyzed Ketonization Reaction for Biofuels Applications

Snell¹,

Shanks

2013

ACS Catal.

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The ketonization of small organic acids is a valuable reaction for biorenewable applications. Ceria has long been used as a catalyst for this reaction; however, under both liquid and vapor phase conditions, it was found that given the right temperature regime of about 150-300 °C, cerium oxide, which was previously believed to be a stable catalyst for ketonization, can undergo bulk transformations. This result, along with other literature reports, suggest that the long held belief of two separate reaction pathways for either bulk or surface ketonization reactions are not required to explain the interaction of cerium oxide with organic acids. X-ray photon spectroscopy, scanning electron microscopy, and temperature programmed decomposition results supported the formation of metal acetates and explained the occurrence of cerium reduction as well as the formation of cerium oxide/acetate whiskers. After thermogravimetry/mass spectrometry and FT-IR experiments, a single reaction sequence is proposed that can be applied to either surface or bulk reactions with ceria. ABSTRACT: The ketonization of small organic acids is a valuable reaction for biorenewable applications. Ceria has long been used as a catalyst for this reaction; however, under both liquid and vapor phase conditions, it was found that given the right temperature regime of about 150−300°C, cerium oxide, which was previously believed to be a stable catalyst for ketonization, can undergo bulk transformations. This result, along with other literature reports, suggest that the long held belief of two separate reaction pathways for either bulk or surface ketonization reactions are not required to explain the interaction of cerium oxide with organic acids. X-ray photon spectroscopy, scanning electron microscopy, and temperature programmed decomposition results supported the formation of metal acetates and explained the occurrence of cerium reduction as well as the formation of cerium oxide/acetate whiskers. After thermogravimetry/mass spectrometry and FT-IR experiments, a single reaction sequence is proposed that can be applied to either surface or bulk reactions with ceria.

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Section: Acs Catalysissupporting

confidence: 82%

Insights into the Ceria-Catalyzed Ketonization Reaction for Biofuels Applications

Snell¹,

Shanks

2013

ACS Catal.

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“…(Note that their experiments were carried out on Pd/SiO 2 at gas phase conditions). In addition, our results are supported by data of Murzin et al [21] observed a decrease in selectivity to alkanes by 8% when they increased acid chain length from SA (C 18 ) to behenic acid (C 20 ). They did not investigate the effect of smaller acid chain length.…”

Section: Catalytic Test Runssupporting

confidence: 90%

“…Kubicková et al reported on the decarboxylation of SA, ethyl stearate and tristearine over carbon supported metal catalysts leading to heptadecane [24]. There were no evidences for the formation of fatty alcohols and almost no octadecane was found, suggesting that the used catalysts were not able to promote hydrodecarboxylation [21]. Snåre et al [10] reported on the decarboxylation of SA to heptadecane in a semi-batch reactor at 300˚C and ca.…”

Section: Introductionmentioning

confidence: 99%

Impact of Chain Length of Saturated Fatty Acids during Their Heterogeneously Catalyzed Deoxygenation

Mohite¹,

Armbruster²,

Richter³

et al. 2014

JSBS

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Fatty acids with different chain length were deoxygenated in the absence of hydrogen (caprylic acid (CA), lauric acid (LA) and stearic acid (SA)). The catalytic tests were carried over Pd-containing catalysts out in a batch reactor under inert gas for 6 h at 250˚C to 350˚C and pressures from 18 to 75 bar in the absence of additionally fed hydrogen. Pd-containing catalysts were tested; the best performing catalyst was 10% Pd/C with 63% undecane yield at 327˚C. These catalysts were used for a comparative decarboxylation of CA, LA and SA. At equal reaction conditions (300˚C, 6 h), the chain length of the fatty acid had a strong impact on the conversion, which was steadily increasing, whereas the alkane selectivity ran through a maximum. This work demonstrated the usability of Pd-containing catalysts for the decarboxylation of various fatty acids in the absence of additionally fed hydrogen with respect to the manufacture of hydrocarbons that can be used as blending components for fuels.

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“…Abstraction of an α-hydrogen atom from the acetate anion oriented parallel to the surface of the catalyst leads to the formation of an alkylidene group which in turn reacts with a neighboring carboxylate and hydrogen to form acetone, water, and CO2. 39,40 To evaluate these potential mechanisms, solid residues were permission has been granted for this version to appear in e-Publications@Marquette. American Chemical Society does not grant permission for this article to be further copied/distributed or hosted elsewhere without the express permission from American Chemical Society.…”

mentioning

confidence: 99%

Thermal Degradation of Acetate-Intercalated Hydroxy Double and Layered Hydroxy Salts

Kandare

Hossenlopp

2006

Inorg. Chem.

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Synopsis:The gas-phase products from thermal degradation of zinccontaining layered metal hydroxides with intercalated acetate anions depend on the identity of metals in the hydroxide layers. Zinc hydroxy acetate and zinc/nickel hydroxy acetate precursors promote ketonization to produce acetone while this channel is suppressed in zinc copper hydroxy acetate. Growth of ZnO crystallites is also precursor dependent.NOT THE PUBLISHED VERSION; this is the author's final, peer-reviewed manuscript. The published version may be accessed by following the link in the citation at the bottom of the page.Inorganic Chemistry, Vol 45, No. 9 (April 2006): pg. 3766-3773. DOI. This article is © American Chemical Society and permission has been granted for this version to appear in e-Publications@Marquette. American Chemical Society does not grant permission for this article to be further copied/distributed or hosted elsewhere without the express permission from American Chemical Society. 2 AbstractTwo hydroxy double salts (HDSs), zinc copper hydroxy acetate (ZCA) and zinc nickel hydroxy acetate (ZNA), and an analogous layered compound, zinc hydroxy acetate (ZHA), have been prepared by a coprecipitation method. The thermal degradation of these materials was characterized via thermogravimetric analysis (TGA), differential thermal analysis (DTA), and TGA coupled with Fourier transform infrared spectroscopy of gas-phase products, TGA-FTIR. Loss of physisorbed and interlayer H2O was observed between 50 and 150 °C for all compounds. Acetic acid, acetone, water, and CO2 were released at high temperatures with relative acetone yields found to be dependent on precursor identity, with very little formed from ZCA compared with ZHA and ZNA. Combined FTIR and XRD analysis of solid residues extracted at different points in the heating profile suggests that ketonization occurs via dissociative adsorption of acetic acid on ZnO surfaces. Nanometer-sized ZnO particles were formed from ZHA, showing slight preferential growth in the ZnO (002) lattice direction, while the presence of a second metal, Ni or Cu, served to retard ZnO crystallite growth at temperatures below 600 °C and eliminate preferential growth. ZCA leads to the formation of reduced copper species (metallic copper and Cu2O) when heated to 250 °C.

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Reactions of Carboxylic Acids on Oxides

Cited by 170 publications

References 0 publications

Insights into the Ceria-Catalyzed Ketonization Reaction for Biofuels Applications

Insights into the Ceria-Catalyzed Ketonization Reaction for Biofuels Applications

Impact of Chain Length of Saturated Fatty Acids during Their Heterogeneously Catalyzed Deoxygenation

Thermal Degradation of Acetate-Intercalated Hydroxy Double and Layered Hydroxy Salts

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