Search results for "Catalytic oxidation"
showing 10 items of 45 documents
Photocatalytic and Catalytic Oxidation of 2-Propanol over Au/TiO2-CeO2 Catalysts
2016
Photocatalytic and catalytic oxidation of 2-propanol (representative VOC’s compound) were compared over mixed (Au)TiO2-CeO2-based catalysts. The role of support in Au catalyzed oxidation reaction under photo and dark conditions was studied. In the photocatalytic oxidation CeO2 had a negative effect on the performance towards the alcohol conversion of both TiO2-CeO2 and Au/TiO2-CeO2 catalysts, being Au/TiO2 the most active system. On the contrary mixed TiO2-CeO2 and Au/TiO2- CeO2 samples showed a higher catalytic oxidation efficiency for 2-propanol conversion compared to the single oxides.
Reactor model for fast reactions in the micro-bubble column and validation
2007
A simple reactor model for predicting conversions in a micro-bubble column is described. It assumes fast reactions so that the gaseous component is readily consumed at the gas-liquid interface. Then, gas-liquid mass transfer becomes determining. As input parameters for the model, the hydrodynamics, specific interfacial area, and mass transport need to be described. Two fast model reactions, the catalytic oxidation of butyraldehyde and the absorption of CO2 in aqueous NaOH, show the applicability of the model but also its limits. The model was used for predicting reaction performance in dependence of operating conditions, in particular to get maximum conversion with the antagonistic paramete…
The influence of ultrasound on the RuI3-catalyzed oxidation of phenol: Catalyst study and experimental design
2009
Abstract The influence of ultrasound at 24 kHz on the heterogeneous aqueous oxidation of phenol over RuI3 with hydrogen peroxide (H2O2) was studied isothermally at 298 K. Effect of ultrasound irradiation on catalytic properties and performance of RuI3 has been studied in details by means of scanning electron microscopy (SEM), X-ray powder diffraction (XRD), dispersion analyzer and a surface analyzer. Turn over frequency of the catalyst was also calculated. In this work, experimental design methodology was applied to optimize the degradation of phenol in aqueous solution, while minimizing an excessive consumption of chemical reagents. The independent variables considered were the catalyst lo…
Carbon nitride nanosheets for the selective photocatalytic oxidation of 5-hydroxymethyl-2-furfural to 2,5-furandicarboxyaldehyde in water suspension
2017
Carbon nitride nanosheets for the selective photocatalytic oxidation of 5-hydroxymethyl-2-furfural to 2,5-furandicarboxyaldehyde in water suspension
Selective photocatalytic oxidation of 5-hydroxymethyl-2-furfural to 2,5-furandicarboxyaldehyde in aqueous suspension of g-C3N4
2017
Graphitic carbon nitride assisted partial photocatalytic oxidation of 5-hydroxymethyl-2-furfural (HMF) in aqueous medium was investigated. Different carbon nitride precursors were considered, being melamine the one yielding the most efficient photocatalyst. The obtained 30% selectivity of HMF oxidation to 2,5-furandicarboxaldehyde (FDC) is higher than those reported up to now. A further thermal exfoliation of the g-C3N4 samples showed under artificial light irradiation both an enhanced photocatalytic activity in conversion of HMF, and selectivity (ca. 42–45%) to FDC. The performance of the catalysts increased when the experiments were carried out under real outdoor illumination, reaching 50…
A comparison between photocatalytic and catalytic oxidation of 2-Propanol over Au/TiO2-CeO2 catalysts
2016
Abstract Photocatalytic and catalytic oxidation of 2-propanol, representative of volatile organic compounds (VOC’s), were compared over mixed TiO 2 –CeO 2 -based catalysts. The effect of different amounts of CeO 2 and the presence of gold (1 wt%) on TiO 2 was investigated. In the photocatalytic oxidation CeO 2 had a negative effect on the performance towards the alcohol conversion of both TiO 2 –CeO 2 and Au/TiO 2 –CeO 2 catalysts, being Au/TiO 2 the most active system. On the contrary mixed TiO 2 –CeO 2 and Au/TiO 2 –CeO 2 samples showed a higher catalytic oxidation efficiency for 2-propanol conversion compared to the single oxides. In this case Au/CeO 2 catalyst had the best performance. …
Intramolecular proton transfer boosts water oxidation catalyzed by a Ru complex
2015
We introduce a new family of complexes with the general formula [Run(tda)(py)2]m+ (n = 2, m = 0, 1; n = 3, m = 1, 2+; n = 4, m = 2, 32+), with tda2– being [2,2′:6′,2″-terpyridine]-6,6″-dicarboxylate, including complex [RuIV(OH)(tda-κ-N3O)(py)2]+, 4H+, which we find to be an impressive water oxidation catalyst, formed by hydroxo coordination to 32+ under basic conditions. The complexes are synthesized, isolated, and thoroughly characterized by analytical, spectroscopic (UV–vis, nuclear magnetic resonance, electron paramagnetic resonance), computational, and electrochemical techniques (cyclic voltammetry, differential pulse voltammetry, coulometry), …
Catalytic Oxidation of Alkanes and Alkenes by H 2 O 2 with a μ‐Oxido Diiron(III) Complex as Catalyst/Catalyst Precursor
2015
A new mu-oxo diiron(III) complex of the lithium salt of the pyridine-based unsymmetrical ligand 3-[(3-{[bis(pyridin-2-ylmethyl)amino]methyl}-2-hydroxy-5-methylbenzyl)(pyridin2-ylmethyl)amino] propanoate (LiDPCPMPP), [Fe-2(mu-O)(LiDPCPMPP)(2)](ClO4)(2), has been synthesized and characterized. The ability of the complex to catalyze oxidation of several alkanes and alkenes has been investigated by using CH3COOH/H2O2 (1:1) as an oxidative system. Moderate activity in cyclohexane oxidation (TOF = 33 h(-1)) and good activity in cyclohexene oxidation (TOF = 72 h(-1)) were detected. Partial retention of configuration (RC = 53%) in cis- and trans-1,2-dimethylcyclohexane oxidation, moderate 3 degrees…
Heterogeneous catalytic degradation of phenolic substrates: catalysts activity
2009
This review article explored the catalytic degradation of phenol and some phenols derivates by means of advanced oxidation processes (AOPs). Among them, only the heterogeneous catalyzed processes based on catalytic wet peroxide oxidation. catalytic ozonation and catalytic wet oxidation were reviewed. Also selected recent examples about heterogeneous photocatalytic AOPs; will be presented. In details, the present review contains: (i) data concerning catalytic wet peroxide oxidation of phenolic compounds over metal-exchanged zeolites, hydrotalcites, metal-exchanged clays and resins. (ii) Use of cobalt-based catalysts, hydrotalcite-like compounds, active carbons in the catalytic ozonation proc…
Catalytic oxidation and reduction of polycyclic aromatic hydrocarbons (PAHs) present as mixtures in hydrothermal media
2012
Author's version of an article in the journal: Polycyclic Aromatic Compounds. Also available from the publisher at: http://dx.doi.org/10.1080/10406638.2012.663451 The reactivity of fluorene, anthracene, and fluoranthene under oxidation and reduction conditions were investigated in this study. This project looks at catalytic and green approaches of converting PAHs to less toxic and/or less stable derivatives that are amenable to further degradation. Hydrothermal reactions have been performed at 300°C with pure H2O and Nafion-SiO2 catalyst for oxidation, and pure H2O, HCOOH, Pd-C, and Nafion-SiO2 catalysts for reductive hydrogenation. Time series has been performed for both the oxidation and …