Liquid-phase Oppenauer oxidation of primary allylic and benzylic alcohols to corresponding aldehydes by solid zirconia catalysts

Liu, Shu Hua; Chuah, Gaik‐Khuan; Jaenicke, Stephan

doi:10.1016/j.molcata.2004.06.013

Cited by 21 publications

(6 citation statements)

References 16 publications

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“…As for the reduction of furfural, in contrast with the results provided by other authors for the reduction of aldehydes in presence of similar catalytic systems to those applied hereby [22,33], furfural is converted in a lower extension, as compared to the other tested molecules, into its corresponding alcohol, probably as a consequence of two different reasons: the lower reactivity of the carbonyl group due to the electron donating nature of the furan ring, and the planar adsorption mode of the same onto the support surface silanol groups [34] thus leading to a competition with the adsorption on zirconium active sites and reducing the MPV reaction rate. However, the high interest for furfuryl alcohol, which serves as starting material in numerous organic syntheses [35] and the simplicity of the catalytic system, has prompted us to investigate the influence of several operation parameters looking for the best reaction conditions to enhance this transformation.…”

Section: Mpv Reduction Of Cyclohexanonementioning

confidence: 41%

Zr-SBA-15 Lewis Acid Catalyst: Activity in Meerwein Ponndorf Verley Reduction

et al. 2015

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Zr-SBA-15 Lewis acid catalyst has demonstrated an outstanding catalytic activity in the reduction of several carbonyl compounds by means of Meerwein Ponndorf Verley (MPV) reaction, using several secondary alcohols, and showing a very high selectivity towards the desired products. Special focus was addressed in the catalytic activity of Zr-SBA-15 material in the production of furfuryl alcohol from furfural, which is an important reaction for the lignocellulosic biomass valorization. In this transformation, both the reaction temperature and the i-PrOH:Furfural molar ratio exert a positive influence on the rate of the MPV transformation, with the influence of the former being much higher.i-propyl-furfuryl ether, a by-product resulting from the etherification of the target product with the sacrificing alcohol, is also found together with the main product. The production of this side-product is highly influenced by the reaction temperature, so that low temperatures and high sacrificing alcohol to substrate molar ratios have to be applied to keep its production at low levels.

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Section: Mpv Reduction Of Cyclohexanonementioning

confidence: 41%

Zr-SBA-15 Lewis Acid Catalyst: Activity in Meerwein Ponndorf Verley Reduction

et al. 2015

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“…ZrO 2 -containing catalysts have evoked recent interest both as additives to other catalytic systems and as isolated entities as well as for their ability to improve the structural integrity of various catalysts and to induce beneficial steering of reaction pathways to increase the respective selectivity of especially the methanol steam reforming (MSR) and methanol synthesis reactions [1][2][3][4][5][6]. Particularly rewarding in this respect is to focus on the Cu-ZrO 2 system, where the addition of ZrO 2 to the industrially the discussion.…”

Section: Introductionmentioning

confidence: 99%

A Comparative Discussion of the Catalytic Activity and CO2-Selectivity of Cu-Zr and Pd-Zr (Intermetallic) Compounds in Methanol Steam Reforming

et al. 2017

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Abstract:The activation and catalytic performance of two representative Zr-containing intermetallic systems, namely Cu-Zr and Pd-Zr, have been comparatively studied operando using methanol steam reforming (MSR) as test reaction. Using an inverse surface science and bulk model catalyst approach, we monitored the transition of the initial metal/intermetallic compound structures into the eventual active and CO 2 -selective states upon contact to the methanol steam reforming mixture. For Cu-Zr, selected nominal stoichiometries ranging from Cu:Zr = 9:2 over 2:1 to 1:2 have been prepared by mixing the respective amounts of metallic Cu and Zr to yield different Cu-Zr bulk phases as initial catalyst structures. In addition, the methanol steam reforming performance of two Pd-Zr systems, that is, a bulk system with a nominal Pd:Zr = 2:1 stoichiometry and an inverse model system consisting of CVD-grown ZrO x H y layers on a polycrystalline Pd foil, has been comparatively assessed. While the CO 2 -selectivity and the overall catalytic performance of the Cu-Zr system is promising due to operando formation of a catalytically beneficial Cu-ZrO 2 interface, the case for Pd-Zr is different. For both Pd-Zr systems, the low-temperature coking tendency, the high water-activation temperature and the CO 2 -selectivity spoiling inverse WGS reaction limit the use of the Pd-Zr systems for selective MSR applications, although alloying of Pd with Zr opens water activation channels to increase the CO 2 selectivity.

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“…Liu et al [208] found that grafted zirconium 1-propoxide on MCM-41 and silica gel were active catalysts in the Oppenauer oxidation of geraniol with furfural with high selectivity to the desired citral. However, when an acidic support such as Al-MCM-41 was used, the selectivity was low, since the catalyst promotes the dehydration and isomerization of geraniol (Scheme 25.40).…”

Section: Catalyst (Mg) T (H) Total Conversion (%) Overall Selectivitymentioning

confidence: 99%