Oxidation Of Acetone Research Articles

Investigation of hybrid plasma-catalytic removal of acetone over CuO/γ-Al2O3 catalysts using response surface method

In this work, plasma-catalytic removal of low concentrations of acetone over CuO/γ-Al2O3 catalysts was carried out in a cylindrical dielectric barrier discharge (DBD) reactor. The combination of plasma and the CuO/γ-Al2O3 catalysts significantly enhanced the removal efficiency of acetone compared to the plasma process using the pure γ-Al2O3 support, with the 5.0 wt% CuO/γ-Al2O3 catalyst exhibiting the best acetone removal efficiency of 67.9%. Catalyst characterization was carried out to understand the effect the catalyst properties had on the activity of the CuO/γ-Al2O3 catalysts in the plasma-catalytic reaction. The results indicated that the formation of surface oxygen species on the surface of the catalysts was crucial for the oxidation of acetone in the plasma-catalytic reaction. The effects that various operating parameters (discharge power, flow rate and initial concentration of acetone) and the interactions between these parameters had on the performance of the plasma-catalytic removal of acetone over the 5.0 wt% CuO/γ-Al2O3 catalyst were investigated using central composite design (CCD). The significance of the independent variables and their interactions were evaluated by means of the Analysis of Variance (ANOVA). The results showed that the gas flow rate was the most significant factor affecting the removal efficiency of acetone, whilst the initial concentration of acetone played the most important role in determining the energy efficiency of the plasma-catalytic process.

Slow large-scale supramolecular structuring as a cause of kinetic anomalies in the liquid-phase oxidation with nitric acid

Isothermal calorimetry, static and dynamic light scattering, and NMR spectroscopy studies provided evidence for slow formation of large associates of solvates in aqueous solutions of nitric acid, which makes it possible to attribute the anomalous kinetic features in the oxidation of acetone to the supramolecular mechanism of the reaction.

Promotional effects of manganese on the structure and activity of Ce–Al–Si based catalysts for low-temperature oxidation of acetone

Low-temperature catalytic oxidation of acetone over metal (M=Cu, Co, Ni, Mn, Fe)-modified cerium oxide supported on Al-containing MSPs (mesoporous silica particles) was studied. The activity tests on various mixed oxides of Cu–Ce, Co–Ce, Ni–Ce, Mn–Ce and Fe–Ce supported on Al-MSPs demonstrated that Ce was the main active species in catalytic oxidation of acetone, while Mn functioned as an appropriate promoter for improving the activity of Ce/Al-MSPs catalyst. The promoting effects of Mn on the structure and activity of Ce/Al-MSPs were investigated. Results showed that the amounts of Mn had significant influences on the catalyst structure, chemical state, redox behavior and surface adsorption ability of the catalysts. Among the catalysts studied, Mn–Ce/Al-MSPs with a Mn/Ce molar ratio of 2/1 was found to be the most active catalyst for achieving maximum acetone activity at temperature of 100–200°C, and it showed much better catalytic performance in comparison with those of Ce/Al-MSPs and Mn/Al-MSPs alone. The superior activity could be attributed to the synergistic effect existing in MnCeOx mixed oxides, resulting in higher amount of Ce3+ and Mn4+ species and enhanced surface reducibility on the catalyst surface and improved acetone adsorption ability, as confirmed by the XPS, H2-TPR and acetone-TPD analyses. In addition, Mn–Ce(2/1)/Al-MSPs showed a remarkable stability at 175°C after being used for 55h.

Partial Oxidation of Alcohols on Visible-Light-Responsive WO3 Photocatalysts Loaded with Palladium Oxide Cocatalyst

Particles of tungsten oxide loaded with a palladium oxide cocatalyst (PdOx/WO3) exhibit higher selectivity in comparison to other photocatalysts, such as Pt/WO3, Pd/TiO2, and Pt/TiO2, in the partial oxidation of alcohols such as 2-propanol to the corresponding aldehydes or ketones (e.g., 80% selectivity for acetone production with ca. 96% conversion of 2-propanol) in water containing molecular O2. A detailed investigation of 2-propanol oxidation as a model reaction revealed significant differences between the reactivities of the WO3 and TiO2 systems. On TiO2 photocatalysts, complete decomposition to CO2 proceeded readily, due to the occurrence of direct oxidation of 2-propanol and acetone adsorbed by holes, resulting in significantly low selectivity for partial oxidation. On the other hand, the rates of acetone peroxidation on WO3 photocatalysts were much lower than those on TiO2 due to the low affinity of the WO3 surface to the substrates, particularly acetone. The low affinity of the WO3 surface also en...

Acetone and ethanol vapor oxidation via negative atmospheric corona discharge over titania-based catalysts

The paper is devoted to the oxidation of acetone and ethanol vapors by means of an optimized negative atmospheric corona discharge combined with TiO2-based catalysts located in a post-plasma position. A series of studied samples includes CuO-MnO2/TiO2, CuO/TiO2 and MnO2/TiO2 with 3wt% of copper oxide and 6.8wt% of manganese oxide. Experiments were performed at room temperature in a closed 404-L chamber with a ∼0.9-L active plasma region. It was shown that the use of the catalysts can provide a significant reduction in the concentrations of ozone and oxidation byproducts and a three-fold increased conversion of the reactants. It was unexpectedly found that copper oxide, as an active agent, did not significantly change the effect of post-plasma-located TiO2. The manganese-containing sample was found to be the best catalyst at the conditions considered. The presence of this catalyst in the post-plasma position inhibits the formation of unwanted products (O3 and CO) and promotes the deep oxidation of acetone and ethanol with increased selectivity toward CO2.

Electrospinning synthesis of vanadium–TiO2–carbon composite nanofibrous membranes as effective catalysts for the complete oxidation of low-concentration acetone

TiO2–carbon and vanadium–TiO2–carbon composite nanofibrous membranes were synthesized through electrospinning and investigated for the complete oxidation of low-concentration acetone. The novel nanofibrous membranes were characterized through various techniques, including TG/DSC, SEM-EDX, HRTEM, XRD, N2 sorption, XPS, NH3-TPD, and H2-TPR analyses. Introduction of vanadium at an appropriate amount enhances the catalytic performance in complete acetone oxidation. The best result was obtained with 10V–TiC nanofibers that contain 10wt.% vanadium. Furthermore, the 10V–TiC nanofibers displayed higher activity than that of the V2O5/TiO2 reference catalyst prepared by impregnation method. Characterization results indicate that these fibers exhibit a typical nanofibrous morphology. Vanadium incorporation accelerates the decomposition of the gel precursor nanofibers and causes variations in textural properties, surface chemistry, acidity, and reducibility. The high porosity of the nanofibrous structure, abundant adsorbed oxygen species on the surface, strong acidity, and reducibility enhance the catalytic performance.

Study of 2-Propanol, 1-Propanol, and Acetone Electrochemical Oxidation on Pt in Gelled Phosphoric Acid at 170 °C

Electrochemical oxidation of acetone, 2-propanol, and 1-propanol on Pt was studied by slow scan rate voltammetry at 170 °C using fuel cell with the membrane of the H3PO4 doped polybenzimidazole. Reaction rate orders with respect to partial pressures of the aliphatic compounds and water vapors were determined at E = 0.5 V and at E = 0.9 V, which correspond to low and high surface oxide coverages on Pt. At E = 0.5 V close to zero reaction rate orders in respect to vapor pressures of aliphatic reactants were found. At E = 0.5 V reaction, rate orders with respect to water vapor pressure were slightly higher than unity in all cases. At E = 0.9 V oxidation, reaction rate orders with respect to aliphatic reactant vapor pressure ranged within 0.6–1. Close to zero reaction rate orders with respect to water vapor pressure were found in all cases at E = 0.9 V.

Preparation, characterization and catalytic properties of yttrium-zirconium-pillared montmorillonite and their application in supported Ce catalysts

AbstractA new yttrium-zirconium-pillared montmorillonite (Y-Zr-MMT), was synthesized, characterized and used as a Ce catalyst support. The Y-Zr-MMT is a good support for dispersing cerium active sites and it is responsible for the high activity in the total oxidation of acetone, toluene and ethyl acetate. The Y-Zr-MMT shows greater advantages than the conventional alumina/cordierite honeycomb supports such as large specific surface area, lower cost and easier preparation. Catalytic tests demonstrated that Ce/Y-Zr-MMT (Ce loading 8.0%) was the most active, with the total oxidation of acetone, toluene and ethyl acetate being achieved at 220, 300 and 220°C, respectively. The catalyst displayed better activity for the oxidation of acetone and ethyl acetate than a conventional, supported Pd-catalyst under similar conditions. The special structure of the yttrium-doped zirconium-pillared montmorillonite can strengthen the interaction between the CeO2 and Zr-MMT support and improve the dispersion of the Ce particles, which enhances the catalytic activity for the oxidation of VOCs. The new catalyst, 8.0%Ce/Y-Zr-MMT, could be promising for industrial applications due to its high catalytic activity and low cost. The support and the catalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and BET specific surface area measurements.

Photo-catalytic oxidation of acetone on a TiO2 powder: An in situ FTIR investigation

In situ transmission infrared spectroscopy was used to investigate the photo-oxidation of acetone on a commercial, oxidized TiO2 (P25) powder catalyst under UV irradiation at ambient temperature, in the absence and presence of gas phase O2. The photochemistry of a number of organic molecules (2-butanone, methanol and acetic acid,) under the same conditions was also studied in order to identify reaction intermediates and products formed in the photo-oxidation of acetone. Under anaerobic conditions (in the absence of gas phase oxygen) limited extent of photo-oxidation of acetone took place on the oxidized TiO2 sample. In the presence of O2 in the gas phase, however, acetone was completely converted to acetates and formates, and ultimately CO2. The initial step in the sequence of photo-induced reactions is the ejection of a methyl radical, resulting in the formation of surface acetates (from the acetyl group) and formates (from the methyl radicals). Acetate ions are also converted to formates, that, in turn, photo-oxidized to CO2. Under the experimental conditions applied the accumulation of carbonates and bicarbonates were observed on the TiO2 surface as the photo-oxidation of acetone proceeded (this was also observed during the course of photo-oxidation of all the other organics studied here). When the initial radical ejection step produced hydrocarbons containing more than one C atoms (as in the case in 2-butanone and mesytil oxide), the formation of aldehydes on the catalyst surface was also observed as a result of secondary reactions.

Catalyst screening for acetone removal in a single-stage plasma-catalysis system

Plasma-catalytic removal of acetone over MOx/γ-Al2O3 (M=Ce, Co, Cu, Mn and Ni) catalysts has been investigated in a dielectric barrier discharge (DBD) reactor. The influence of different catalysts on the plasma-catalytic process has been examined in terms of acetone removal efficiency, CO2 selectivity and the formation of by-products. The combination of plasma with the MOx/γ-Al2O3 catalysts significantly enhances the removal efficiency of acetone and CO2 selectivity, whilst substantially reducing the formation of by-products (HCHO and HCOOH). The maximum removal efficiency of 94.2% and CO2 selectivity of 80.1% were achieved when using the CuOx/γ-Al2O3 catalyst. Introducing the CuOx/γ-Al2O3 catalyst into the plasma system also shows the lowest formation of by-products. Different catalyst characterization techniques have been used to understand the effect of catalyst properties on the plasma reactions. It has been found that the reducibility of the MOx/γ-Al2O3 catalysts plays a dominant role in the plasma-catalytic oxidation of acetone, whilst the specific surface area and pore properties of the catalysts have a very weak effect on the performance of the plasma-catalytic reaction. In addition, a simplified kinetic model has been developed, showing the effect of different catalysts on the acceleration of the plasma-catalytic removal of acetone.

Adsorption and photocatalytic oxidation of acetone and diethyl sulfide on FeOOH aerosol

Superfine FeOOH powder in an aerosol state with a particle size of about 3 nm has been studied in the processes of reactive adsorption and photocatalytic oxidation of acetone and diethyl sulfide vapors in air. The aerosol (5 g) is sprayed with a Helmholtz resonator placed into the center of a 100-L plastic chamber. Spraying is completed in 2 min, and the aerosol settles down within a time of less than 5 min. Rapid partial adsorption of acetone and diethyl sulfide on aerosol nanoparticles with characteristic times of 1 and 1.3 min, respectively, has been observed. FeOOH exhibits no photocatalytic activity with respect to acetone oxidation. Diethyl sulfide is oxidized with the formation of acetaldehyde as an intermediate product and CO and CO2 as the final products.

Controllable synthesis of novel hierarchical V2O5/TiO2 nanofibers with improved acetone oxidation performance

A controllable strategy to fabricate novel hierarchical V2O5/TiO2 nanofiber catalysts was proposed. The catalysts were found to present high oxidation performance for acetone. The reaction mechanism of catalytic oxidation was also investigated.

Acetone Gas Sensing Properties of a Multiple‐Networked Fe2O3‐Functionalized CuO Nanorod Sensor

Fe2O3‐decorated CuO nanorods were prepared by Cu thermal oxidation followed by Fe2O3 decoration via a solvothermal route. The acetone gas sensing properties of multiple‐networked pristine and Fe2O3‐decorated CuO nanorod sensors were examined. The optimal operating temperature of the sensors was found to be 240°C. The pristine and Fe2O3‐decorated CuO nanorod sensors showed responses of 586 and 1,090%, respectively, to 1,000 ppm of acetone at 240°C. The Fe2O3‐decorated CuO nanorod sensor also showed faster response and recovery than the latter sensor. The acetone gas sensing mechanism of the Fe2O3‐decorated CuO nanorod sensor is discussed in detail. The origin of the enhanced sensing performance of the multiple‐networked Fe2O3‐decorated CuO nanorod sensor to acetone gas was explained by modulation of the potential barrier at the Fe2O3‐CuO interface, highly catalytic activity of Fe2O3 for acetone oxidation, and the creation of active adsorption sites by Fe2O3 nanoparticles.

A comparative investigation on the low-temperature catalytic oxidation of acetone over porous aluminosilicate-supported cerium oxides

The performance of cerium oxide supported on mesoporous aluminosilicate particles (Al-MSPs) with a nominal Ce and Al loading of 2.8 and 1.2wt.%, respectively, was evaluated for the low-temperature oxidation of acetone. The influence of the preparation methods, including one-step aerosol-assisted self-assembly (AASA) method and post-synthetic wet impregnation method, was examined. The results showed that the surface area and pore diameter of Ce/Al-MSPs(50/25) prepared by AASA method were similar to those of Ce–Al-MSPs made via traditional impregnation method, while a better metallic dispersion of Ce and Al oxide species on Ce/Al-MSPs(50/25) was observed as compared to that of Ce–Al-MSPs. The catalytic performances of Ce/Al-MSPs(50/25) and Ce–Al-MSPs were compared with that of cerium-impregnated H–ZSM-5 (Ce–ZSM-5) zeolite catalyst. The activity of freshly made catalysts followed the order: Ce/Al-MSPs(50/25)>Ce–ZSM-5>Ce–Al-MSPs. The superior catalytic behavior of the Ce/Al-MSPs(50/25) could be due to the combined effect of strong surface reducibility and high acid property. Although Ce–ZSM-5 and Ce–Al-MSPs presented high activity for acetone removal in the beginning, their activities quickly decreased due to the coking effect. In contrast, Ce/Al-MSPs(50/25) showed a good stability during a 24h test at the reaction temperature of 150°C. Both surface reducibility and acidity played crucial roles for their high catalytic performance and high stability at low temperatures.

Adsorption and plasma-catalytic oxidation of acetone over zeolite-supported silver catalyst

The abatement of acetone using a combination of non-thermal plasma, catalysis and adsorption was investigated in a dielectric barrier discharge plasma reactor packed with silver-coated zeolite pellets serving as both adsorbent and catalyst. The removal of acetone in this reactor system was carried out by cyclic operation comprising two repetitive steps, namely, adsorption followed by plasma-catalytic oxidation. The effects of the zeolite-supported silver catalyst on the reduction of unwanted ozone emission and the behavior for the formation of gaseous byproducts were examined. The experimental results showed that the zeolite-supported catalyst had a high acetone adsorption capacity of 1.07 mmol g−1 at 25 °C. Acetone with a concentration of 300 ppm was removed from the gas stream and enriched on the zeolite surface during the adsorption step of the cyclic process (100 min). In the succeeding step, the adsorbed acetone was plasma-catalytically treated under oxygen-flowing atmosphere to recover the adsorption capability of the surface. The plasma-catalytic oxidation of the acetone adsorbed in the previous 100 min adsorption step was completed in 15 min. The abatement of acetone by the cyclic adsorption and plasma-catalytic oxidation process was able to increase the performance of the reactor with respect to the energy efficiency, compared to the case of continuous plasma-catalytic treatment. The use of the zeolite-supported silver catalyst largely decreased the emission of unreacted ozone and increased the amount of gaseous byproducts such as carbon oxides and aldehydes due to the enhanced oxidation of the adsorbed acetone and intermediates.

Photocatalytic films for soil fumigation: Control of dimethyl disulfide concentration after fumigation

The photocatalytic oxidation of dimethyl disulfide (DMDS), a large spectrum and efficient fumigant, was studied with newly developed industrial Virtually Impermeable Films including a photocatalytic function. The aim was to define the optimal film composition to decrease DMDS concentration in the air space between the soil and the film at the end of the treatment while keeping an optimal DMDS concentration during the fumigation treatment. From the comparison between various films with different composition (polyethylene (PE) and polyamide (PA) layers together with a photocatalytic layer), number of layers, thickness and TiO2 concentration, it was concluded that for all the samples the light absorption was linearly correlated to TiO2 surface density. The optimal TiO2 content for efficient (98%) light absorption was determined.A first screening of the films was first carried out on the photocatalytic oxidation of acetone. Different diffusion rates of acetone and DMDS inside the PE matrix were deduced from the comparison of the results with the colored black and white films. Complete mineralization of acetone and less extensive mineralization of DMDS (due to formation of methanesulfonate together with sulfates) was observed with most of the studied films. Colored black and white films with suitable design were also efficient for DMDS degradation, but not for acetone mineralization.Since it is known that DMDS and its oxidation products are beneficial for plant growth, it was concluded that colored or uncolored gastight photocatalytic films could be successfully used for wide field fumigation with DMDS by optimizing its degradation rate in the air space for maximum nematicide, fungicide and herbicide efficiency, with decreased buffer zones (area of no fumigation) and maximum safety for neighborhood and workers at the end of the treatment.

A novel acetone sensor utilizing cataluminescence on layered double oxide

This work developed a facile and effective sensor for the determination of acetone, the diabetic biomarker, which was based on cataluminescence (CTL) emission on the surface of layered double oxide (LDO) that is a layered nanomaterial with easy preparation and environmental friendliness. Under the optimized conditions, the linear range of the CTL intensity versus concentration of acetone was 0.1–16mM with the detection limit of 0.02mM (S/N=3). The relative standard deviation (RSD) for 50 repeated measurements of 1.0mM acetone was 3.6%. Interestingly, there was no or weak response to seven common volatile organic compounds (VOCs), including ethanol, heptanal, ethyl acetate, methanol, formaldehyde, acetic acid and toluene. Furthermore, the proposed CTL sensor was successfully used for sensing acetone in human plasma samples of diabetes patients with a satisfactory recovery. The results demonstrated that the proposed CTL sensor had a promising capability for the sensing of acetone in diabetes diagnosis. The possible CTL mechanism from the oxidation of acetone on the surface of LDO was also discussed.

Microbial acetone oxidation in coastal seawater.

Acetone is an important oxygenated volatile organic compound (OVOC) in the troposphere where it influences the oxidizing capacity of the atmosphere. However, the air-sea flux is not well quantified, in part due to a lack of knowledge regarding which processes control oceanic concentrations, and, specifically whether microbial oxidation to CO2 represents a significant loss process. We demonstrate that 14C labeled acetone can be used to determine microbial oxidation to 14CO2. Linear microbial rates of acetone oxidation to CO2 were observed for between 0.75-3.5 h at a seasonally eutrophic coastal station located in the western English Channel (L4). A kinetic experiment in summer at station L4 gave a Vmax of 4.1 pmol L-1 h-1, with a Km constant of 54 pM. We then used this technique to obtain microbial acetone loss rates ranging between 1.2 and 42 pmol L-1 h-1.(monthly averages) over an annual cycle at L4, with maximum rates observed during winter months. The biological turnover time of acetone (in situ concentration divided by microbial oxidation rate) in surface waters varied from ~3 days in February 2011, when in situ concentrations were 3 ± 1 nM, to >240 days in June 2011, when concentrations were more than twofold higher at 7.5 ± 0.7 nM. These relatively low marine microbial acetone oxidation rates, when normalized to in situ concentrations, suggest that marine microbes preferentially utilize other OVOCs such as methanol and acetaldehyde.

Impact of acetone (photo)oxidation on HOxproduction in the UT/LMS based on CARIBIC passenger aircraft observations and EMAC simulations

Until a decade ago, acetone was assumed to be a dominant HOx source in the dry extra-tropical upper troposphere (ex-UT). New photodissociation quantum yields of acetone and the lack of representative data from the ex-UT challenged that assumption. Regular mass spectrometric observations onboard the Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrument Container (CARIBIC) passenger aircraft deliver the first representative distribution of acetone in the UT/LMS (UT/lowermost stratosphere). Based on diverse CARIBIC trace gas data and non-observed parameters taken from the model ECHAM5/MESSy for Atmospheric Chemistry, we quantify the HOx source in the UT/LMS from (photo)oxidation of acetone. The findings are contrasted to HOx production from ozone photolysis, overall the dominant tropospheric HOx source. It is shown that HOx production from acetone (photo)oxidation reaches up to 95% of the HOx source from ozone photolysis in autumn in the UT and on average ~61% in summer. That is, acetone is a significant source of HOx in the UT/LMS.

Plasma-catalytic oxidation of acetone in annular porous monolithic ceramic-supported catalysts

Oxidative decomposition of acetone over multichannel monolithic ceramic-supported catalysts combined with non-thermal plasma was investigated. Plasma was generated inside the porous ceramic by applying an alternating current (AC) voltage to the coaxial electrodes. The tandem plasma-catalytic reactor consisted of two ceramic-supported catalysts containing zinc oxide (ZnO) and/or manganese oxide (MnO2), in which the first supported catalyst was exposed to the plasma discharge and the second one was placed in the post-plasma region. Several sets of catalyst arrangements such as MnO2-loaded monolith followed by bare monolith, ZnO-loaded monolith followed by bare monolith, ZnO-loaded monolith followed by MnO2-loaded monolith and two consecutive MnO2-loaded monoliths with different Mn contents were examined in relation to the acetone decomposition and the byproducts formation. More than 90% of acetone was decomposed at a specific input energy (SIE) of about 1.0 kJ L−1 with the catalyst arrangement of MnO2 (0.1% Mn) followed by MnO2 (5.0% Mn), while the decomposition efficiency obtained with two consecutive bare monoliths was about 66% at the same SIE. The use of ZnO in the plasma discharge region did not largely improve the acetone decomposition efficiency. Wherever it is placed either in the plasma discharge region or in the post-plasma region, MnO2 catalyst substantially promoted the acetone decomposition, obviously due to the dissociation of ozone into far more reactive oxygen atoms available for oxidizing acetone molecules.