Photocatalytic air oxidation of cyclohexane in CH2Cl2–C6H12 mixtures over TiO2 particles

Brusa, M. A.; Iorio, Yesica Di; Churio, María Sandra; Grela, M. A.

doi:10.1016/j.molcata.2006.12.008

Cited by 31 publications

(27 citation statements)

References 43 publications

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“…10 g of support was then added to the solution and aged for 60 min with continuous stirring at 400 rpm. During the ageing period the temperature of the slurry was maintained at 343 K and the pH at 7.5, using 2 M Na 2 CO 3 or 0.5 M HNO 3 . At the end of the ageing time, the slurry was filtered and washed five times; each by re-slurrying in 335 mL of high purity water for 5 min followed by filtration.…”

Section: Catalyst Preparationmentioning

confidence: 99%

“…Approximately 25 mg of each sample was pretreated at 398K and rapidly cooled to 373K followed by loading with ammonia applying a flow of 30 mL min -1 for about 1 h. A He flow of 30 mL min -1 was applied to remove weakly adsorbed NH 3 . A linear temperature program was started (373-873 K at 10K min -1 ), and the desorbed amount of ammonia was analyzed by the TCD.…”

Section: Catalyst Characterizationmentioning

confidence: 99%

“…The current commercial process is very energetically intensive, and several studies have focused on the direct use of photon energy to selectively oxidize cyclohexane at room temperature using a photocatalyst [1][2][3][4][5][6][7][8][9][10][11]. Although a high ketone over alcohol selectivity is obtained in photocatalytic cyclohexane oxidation, a low conversion (quantum efficiency) and rapid catalyst deactivation prevent application in practice.…”

Section: Introductionmentioning

confidence: 99%

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How Gold Deposition Affects Anatase Performance in the Photo-catalytic Oxidation of Cyclohexane

et al. 2009

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Gold deposition on Hombikat UV100 was found to negatively affect the activity of this Anatase catalyst in selective photo-oxidation of cyclohexane. By ammonia TPD and DRIFT spectroscopy it was determined that the Au deposition procedure leads to a significant decrease in OH-group density (mol m -2 BET ) on Hombikat, suggesting that the amount of surface OH-groups, rather than the presence or absence of Au, is determining the catalytic performance. The importance of surface OH-groups was demonstrated by comparing the performance of Hombikat (with and without Au deposition) to surface propoxylated TiO 2 , synthesized by a sol-gel method from titanium (IV) isopropoxide. The effect of the deposition recipe of noble metals on the surface composition of TiO 2 should thus be taken into account in evaluating and explaining photocatalytic performance of TiO 2 modified by noble metals (Au), in particular in non-aqueous phase reactions.

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Section: Catalyst Preparationmentioning

confidence: 99%

Section: Catalyst Characterizationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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How Gold Deposition Affects Anatase Performance in the Photo-catalytic Oxidation of Cyclohexane

et al. 2009

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“…by addition of water [18,19] or solvents [19][20][21] • regeneration of deactivated photocatalysts [22] • optimisation of the operation temperature [23] • optimisation of (the wavelength of) the irradiance [15,24] • optimisation of the oxygen concentration [21] • optimisation of the reactor design [25] • mechanistic understanding [26,27] to allow rational design of improved catalyst materials…”

Section: Introductionmentioning

confidence: 99%

The influence of water vapour on the photocatalytic oxidation of cyclohexane in an internally illuminated monolith reactor

Dijk¹,

Simmelink²,

Mul³

2014

Applied Catalysis A: General

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This paper discusses effects of humidity on photocatalytic cyclohexane oxidation performed in an internally illuminated monolith reactor equipped with an immobilised layer of approximately 3 µm titania (Hombikat uv100). Using dry nitrogen containing 10-20% of oxygen, cyclohexanone is produced with high selectivity (> 90%) over cyclohexanol. The photocatalytic monolith deactivates within 80 minutes of operation. Regeneration of activity of such deactivated monolith is possible by air treatment at 450°C.When the applied nitrogen/oxygen gas is humidified, stable ketone production rates are obtained around 5 · 10 −6 mol h −1 at an optimised relative humidity of 65 %. Ketone over alcohol selectivity is lower in humidified conditions, the ratio of the cyclohexanol/cyclohexanone production rates increases from 0.4 to 1.0 as a function of increasing humidity from 30% to 90%.Rapid transients in water vapour content lead to relatively slow changes in concentration of in situ produced cyclohexanone and cyclohexanol. The observation of these changes are used to explain the effect of humidity on reactor performance.

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“…The selective aerobic oxidation of hydrocarbons is a major goal of today's research in catalysis as selectively oxidized hydrocarbons can be used as feedstock for the preparation of fine chemicals [1,2]. Among the oxidation of various alkanes, partial oxidation of cyclohexane to cyclohexanol and cyclohexanone, the intermediates in manufacturing nylon 6 or nylon 6,6, have attracted commercial interest [3].…”

Section: Introductionmentioning

confidence: 99%

Oxidation of cyclohexane with tert-butylhydroperoxide and hydrogen peroxide catalyzed by nano-sized γ-alumina supported metallophthalocyanines

Ebadi

Nikbakht

2011

Reac Kinet Mech Cat

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In this study, nano-c-alumina-supported unsubstituted Fe-, Co-and Mn-phthalocyanines were prepared and characterized. Catalytic activities of the supported phthalocyanines for the oxidation of cyclohexane with tert-butylhydroperoxide (TBHP) and H 2 O 2 as the oxidant in the liquid phase were considered. For the MPc/nano-c-alumina catalysts, a dimethylformamide:dichloromethane (3:7) solvent mixture was employed. The products of the catalytic reaction are cyclohexanone and cyclohexanol. The conversion percent of cyclohexane depended on the oxidant and the catalyst. TBHP was found to be a better oxidant than H 2 O 2 since minimal destruction of the catalyst and higher conversion of cyclohexane were observed when this oxidant was employed. Under these reaction conditions, the order of catalytic activities is as follows: CoPc/c-alumina [ FePc/c-alumina [ MnPc/c-alumina. Over c-alumina, the conversion was much lower than on supported catalysts. The highest conversion of cyclohexane (13.21%) was observed on 10% CoPc supported.

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Photocatalytic air oxidation of cyclohexane in CH2Cl2–C6H12 mixtures over TiO2 particles

Cited by 31 publications

References 43 publications

How Gold Deposition Affects Anatase Performance in the Photo-catalytic Oxidation of Cyclohexane

How Gold Deposition Affects Anatase Performance in the Photo-catalytic Oxidation of Cyclohexane

The influence of water vapour on the photocatalytic oxidation of cyclohexane in an internally illuminated monolith reactor

Oxidation of cyclohexane with tert-butylhydroperoxide and hydrogen peroxide catalyzed by nano-sized γ-alumina supported metallophthalocyanines

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