Catalytic Combustion of Vinyl Chloride Emission over a TiO2–MnOx Catalyst

2017 ◽  
Vol 42 (3) ◽  
pp. 259-268 ◽  
Author(s):  
Yiling Wan ◽  
Xiangyu Xie ◽  
Xiaojun Chen
Keyword(s):  
Vinyl Chloride ◽  
Catalytic Combustion ◽  
Active Oxygen Species ◽  
Catalyst Activity ◽  
Sol Gel ◽  
Space Velocity ◽  
Catalytic Performance ◽  
Molar Ratio ◽  
Preparation Conditions ◽  
Diffraction Peaks

TiO2–MnO x catalyst samples with different Ti/(Ti + Mn) molar ratios (2:3, 3:4, 4:5, 5:6, 6:7 and 1) prepared by the citric acid (CA) sol-gel method were studied in the catalytic combustion of vinyl chloride (VC) emission. The effects of preparation conditions and operation parameters on the catalytic performance of TiO2–MnO x were investigated. The catalyst samples were characterised by N2 adsorption, X-ray diffraction (XRD) and H2-temperature programmed reduction (H2-TPR). In the catalytic combustion of VC over TiO2–MnO x, products containing HCl, CO2, and H2O were obtained and there were no by-products such as chlorohydrocarbons and chlorine. The TiO2–MnO x catalyst with the molar ratio of CA/Mn/Ti = 0.30:0.20:0.80 showed the best catalytic performance and had better operating flexibility over the ranges of gas hourly space velocity (GHSV) of 15000–100000 h−1 and VC concentration of 0.05–2.00%. The temperatures at 50% conversion (140 °C) and at 99% conversion (220 °C) were achieved at a VC concentration of 0.1% and GHSV of 15000 h−1. XRD characterisation indicated that only the characteristic diffraction peaks of TiO2 with the anatase structure appeared and no characteristic diffraction peaks of MnO x species appeared for the TiO2–MnO x catalyst. XRD and H2-TPR results indicated that Mn ions were incorporated into the TiO2 lattice to form a Ti–Mn–O solid solution, which enhanced the reactivity of active oxygen species on the catalyst surface and thereby promoted the catalyst activity.

Effect of Preparation Conditions on the n-Pentane Isomerisation Performance of Pt-S2O82–/ZrO2–Al2O3 Catalysts Prepared by the Microemulsion Method

2017 ◽  
Vol 42 (1) ◽  
pp. 14-22
Author(s):  
Hua Song ◽  
Yao Meng ◽  
Hualin Song ◽  
Feng Li
Keyword(s):  
Cetyltrimethylammonium Bromide ◽  
Space Velocity ◽  
Catalytic Performance ◽  
Catalyst Preparation ◽  
Molar Ratio ◽  
Mass Ratio ◽  
Microemulsion Method ◽  
Preparation Conditions ◽  
Weight Hourly Space Velocity ◽  
Lower Temperature

Pt-promoted S2O82–/ZrO2–Al2O3 (SZA) catalysts were successfully prepared by the microemulsion (Pt-SZA-M) and impregnation (Pt-SZA-I) methods. The effects of the preparation parameters (surfactant-to-oil ratio, surfactant-to-cosurfactant ratio, types of cosurfactant and oil phase, etc.) on the catalytic activity of Pt-SZA-M catalysts in the isomerisation of n-pentane were investigated. The results showed that the optimal catalyst preparation conditions were: a cetyltrimethylammonium bromide (CTAB)/ n-butanol mass ratio of 4:6, a (CTAB + n-butanol)/cyclohexane mass ratio of 3:7, a content of H2PtCl6 solution in microemulsion of 3.6 wt% and a N2H5OH/H2PtCl6 molar ratio of 25:1. A comparison of the isopentane yield for Pt-SZA-M with that for Pt-SZA-I was also performed. The results showed that the microemulsion method led to smaller and more uniform Pt particles (4.5 nm) on the SZA. In comparison with Pt-SZA-I, the isopentane yield for Pt-SZA-M was increased by 13.5% at 180 °C, showing the catalytic performance of Pt-SZA-M at lower temperature was improved significantly. At a reaction temperature of 230 °C, a pressure of 2.0 MPa, a hydrogen/ n-pentane molar ratio of 4:1 and a weight hourly space velocity of 1.0 h−1, the yield of isopentane for Pt-SZA-M reached 60.8%.

Effect of Fe and Co promoters on CO methanation activity of nickel catalyst prepared by impregnation – co-precipitation method

2020 ◽  
Vol 18 (5-6) ◽  
Author(s):  
Buyan-Ulzii Battulga ◽  
Tungalagtamir Bold ◽  
Enkhsaruul Byambajav
Keyword(s):  
Synergetic Effect ◽  
Space Velocity ◽  
Catalytic Performance ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Alumina Support ◽  
Co Methanation ◽  
Temperature Range ◽  
Co Precipitation ◽  
Catalyst Distribution

AbstractNi based catalysts supported on γ-Al2O3 that was unpromoted (Ni/γAl2O3) or promoted (Ni–Fe/γAl2O3, Ni–Co/γAl2O3, and Ni–Fe–Co/γAl2O3) were prepared using by the impregnation – co-precipitation method. Their catalytic performances for CO methanation were studied at 3 atm with a weight hourly space velocity (WHSV) of 3000 ml/g/h of syngas with a molar ratio of H2/CO = 3 and in the temperature range between 130 and 350 °C. All promoters could improve nickel distribution, and decreased its particle sizes. It was found that the Ni–Co/γAl2O3 catalyst showed the highest catalytic performance for CO methanation in a low temperature range (<250 °C). The temperatures for the 20% CO conversion over Ni–Co/γAl2O3, Ni–Fe/γAl2O3, Ni–Fe–Co/γAl2O3 and Ni/γAl2O3 catalysts were 205, 253, 263 and 270 °C, respectively. The improved catalyst distribution by the addition of cobalt promoter caused the formation of β type nickel species which had an appropriate interacting strength with alumina support in the Ni–Co/γAl2O3. Though an addition of iron promoter improved catalyst distribution, the methane selectivity was lowered due to acceleration of both CO methanation and WGS reaction with the Ni–Fe/γAl2O3. Moreover, it was found that there was no synergetic effect from the binary Fe–Co promotors in the Ni–Fe–Co/γAl2O3 on catalytic activity for CO methanation.

scholarly journals Zinc Acetate Immobilized on Mesoporous Materials by Acetate Ionic Liquids as Catalysts for Vinyl Acetate Synthesis

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Hang Xu ◽  
Tianlong Yu ◽  
Mei Li
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Vinyl Acetate ◽  
Silica Gel ◽  
Catalyst Activity ◽  
Catalyst Layer ◽  
Space Velocity ◽  
Molar Ratio ◽  
Vinyl Acetate Monomer ◽  
Adsorption Desorption

Ionic liquid containing active ingredient Zn(CH3COO)2was loaded in mesoporous silica gel to form supported ionic liquids catalyst (SILC) which was used to synthesize vinyl acetate monomer (VAM). SILC was characterized by1HNMR, FT-IR, TGA, BET, and N2adsorption/desorption and the acetylene method was used to evaluate SILC catalytic activity and stability in fixed reactor. The result shows that 1-allyl-3-acetic ether imidazole acetate ionic liquid is successfully fixed within mesoporous channel of silica gel. The average thickness of ionic liquid catalyst layer is about 1.05 nm. When the catalytic temperature is 195°C, the acetic acid (HAc) conversion is 10.9% with 1.1 g vinyl acetate yield and 98% vinyl acetate (VAc) selectivity. The HAc conversion is increased by rise of catalytic temperature and molar ratio of C2H2 : HAc and decreased by mass space velocity (WHSV). The catalyst activity is not significantly reduced within 7 days and VAc selectivity has a slight decrease.

Mesoporous CoO-supported palladium nanocatalysts with high performance for o-xylene combustion

2018 ◽  
Vol 8 (3) ◽  
pp. 806-816 ◽  
Author(s):  
Shaohua Xie ◽  
Yuxi Liu ◽  
Jiguang Deng ◽  
Jun Yang ◽  
Xingtian Zhao ◽  
...  
Keyword(s):  
High Performance ◽  
Catalytic Combustion ◽  
Active Oxygen Species ◽  
Catalytic Performance ◽  
Active Oxygen ◽  
Oxygen Species ◽  
Highly Active ◽  
Palladium Nanocatalysts ◽  
Supported Palladium

The adsorbed o-xylene species can immediately react with active oxygen species at the highly active Pd–CoO interface between Pd NPs and meso-CoO, thus resulting in good catalytic performance of Pd/meso-CoO for o-xylene catalytic combustion.

scholarly journals BiOCl/TiO2/diatomite composites with enhanced visible-light photocatalytic activity for the degradation of rhodamine B

2019 ◽  
Vol 10 ◽  
pp. 1412-1422 ◽  
Author(s):  
Minlin Ao ◽  
Kun Liu ◽  
Xuekun Tang ◽  
Zishun Li ◽  
Qian Peng ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Rhodamine B ◽  
Sol Gel ◽  
Catalytic Performance ◽  
Light Irradiation ◽  
Molar Ratio ◽  
Visible Light Photocatalytic Activity ◽  
Visible Light Photocatalytic

A BiOCl/TiO2/diatomite (BTD) composite was synthesized via a modified sol–gel method and precipitation/calcination method for application as a photocatalyst and shows promise for degradation of organic pollutants in wastewater upon visible-light irradiation. In the composite, diatomite was used as a carrier to support a layer of titanium dioxide (TiO2) nanoparticles and bismuth oxychloride (BiOCl) nanosheets. The results show that TiO2 nanoparticles and BiOCl nanosheets uniformly cover the surface of diatomite and bring TiO2 and BiOCl into close proximity. Rhodamine B was used as the target degradation product and visible light (λ > 400 nm) was used as the light source for the evaluation of the photocatalytic properties of the prepared BTD composite. The results show that the catalytic performance of the BTD composite under visible-light irradiation is much higher than that of TiO2 or BiOCl alone. When the molar ratio of BiOCl to TiO2 is 1:1 and the calcination temperature is 400 °C, the composite was found to exhibit the best catalytic effect. Through the study of the photocatalytic mechanism, it is shown that the strong visible-light photocatalytic activity of the BTD composite results mainly from the quick migration of photoelectrons from the conduction band of TiO2/diatomite to the surface of BiOCl, which promotes the separation effect and reduces the recombination rate of the photoelectron–hole pair. Due to the excellent catalytic performance, the BTD composite shows great potential for wide application in the field of sewage treatment driven by solar energy.

scholarly journals Synthesis and characterization of some nanostructured composite oxides for low temperature catalytic combustion of dilute propane

RSC Advances ◽  
2017 ◽  
Vol 7 (45) ◽  
pp. 27863-27871 ◽  
Author(s):  
C. Doroftei ◽  
L. Leontie
Keyword(s):  
Low Temperatures ◽  
Catalytic Combustion ◽  
Sol Gel ◽  
Catalytic Performance ◽  
Synthesis And Characterization ◽  
Propane Combustion ◽  
Nanostructured Composite ◽  
Composite Oxides ◽  
Combustion Technique

Five nanosized perovskite and four ferrospinel powders were prepared by sol–gel self-combustion technique. The La0.6Pb0.2Mg0.2MnO3 perovskite was found to exhibit the best catalytic performance with respect to propane combustion at low temperatures.

scholarly journals SOL-GEL DERIVED Co AND Ni BASED CATALYSTS: APPLICATION FOR STEAM REFORMING OF ETHANOL

2010 ◽  
Vol 8 (1) ◽  
pp. 47-53
Author(s):  
Haryo Satriya Oktaviano ◽  
Wega Trisunaryanti
Keyword(s):  
Steam Reforming ◽  
Catalyst Activity ◽  
Sol Gel ◽  
Lewis Acid Site ◽  
Morphological Properties ◽  
Molar Ratio ◽  
Gel Method ◽  
Sol Gel Method ◽  
Steam Reforming Of Ethanol ◽  
Ethanol Steam

Cobalt and nickel based catalysts for ethanol steam reforming have been prepared. Preparation of Na-Ni-Mo/C, Na-Co-Mo/C, K-Ni-Mo/C and K-Co-Mo/C have been carried out using sol-gel method by applying citric acid as complexion agent and source for support formation. Prepared catalyst via sol gel showed tailored morphological properties signed by tailored pore size distribution. The acidity of catalyst showed that all catalysts contain only Lewis acid site. The catalyst activity test was conducted by using semi flow method with molar ratio of ethanol : water = 0.33 at 400 oC   Keywords: sol-gel method, steam reforming, ethanol

Effects of Preparation Conditions on Alkali-Activation Reactivity of Chemosynthetic Al2O3-2SiO2 Powders

2015 ◽  
Vol 1120-1121 ◽  
pp. 123-127
Author(s):  
Dong Huang ◽  
Wan Li Lu ◽  
Jin Ying Pang ◽  
Guo Wei Mo ◽  
Shu Juan Yu ◽  
...  
Keyword(s):  
Calcination Temperature ◽  
Sol Gel ◽  
Magic Angle Spinning ◽  
Molar Ratio ◽  
Alkali Activation ◽  
Magic Angle ◽  
Drying Time ◽  
Preparation Conditions ◽  
Key Factor ◽  
Synthetic Temperature

Pure Al2O3-2SiO2 powders with alkali-activation reactivity were prepared by a sol-gel method. The effects of preparation conditions on alkali-activation reactivity were studied and the optimum preparation conditions were obtained. The results show that calcination temperature is a key factor affecting the alkali-activation reactivity of the powders, while other preparation conditions such as synthetic temperature, the molar ratio of solvents to starting materials and drying time have fewer effects on alkali-activation reactivity than calcination temperature. The structure of the powders was investigated by 27Al magic-angle spinning nuclear magnetic resonance spectra. The data show that the Al2O3-2SiO2 powders with the high alkali-activation reactivity are of high content of 5-coordinated Al and the peaks attributed to 5-coordinated Al are strengthened with the rise of calcination temperature of the powders.

Low-Temperature Catalytic Combustion of VOCs over MnOx–ZnO Mixed Oxides Supported on Cordierite Ceramic

2014 ◽  
Vol 989-994 ◽  
pp. 671-675
Author(s):  
Qiong Huang ◽  
Ying Wen Chen ◽  
Shu Bao Shen ◽  
Min Dong Chen
Keyword(s):  
Low Temperature ◽  
High Activity ◽  
Calcination Temperature ◽  
Catalytic Combustion ◽  
Mixed Oxides ◽  
Molar Ratio ◽  
Complete Combustion ◽  
Preparation Conditions ◽  
Cordierite Ceramic ◽  
And Performance

Catalytic combustion of VOCs was investigated over Mn–Zn mixed oxides supported on cordierite ceramic (Cord) and over the promoted Mn-Zn oxides with γ–Al2O3 coating. The properties and performance were characterized by using the XRD, SEM, BET, and TPD techniques. Mn-Zn oxides catalysts with different kinds of γ–Al2O3 sol coating were found to possess a high activity, and the Mn–Zn/γ–Al2O3/Cord (Mn/Zn=2) was identified as the most active that the temperature of complete combustion of toluene was 250°C. Effects of variation of preparation conditions, including molar ratio of Mn and Zn, loading, calcination temperature and different kinds of γ–Al2O3 dipping were investigated.

Effect of Synthesis Conditions on Photocatalytic Activities of Nanoparticulate TiO2

2011 ◽  
Vol 299-300 ◽  
pp. 604-607
Author(s):  
Yan Jun Zhou ◽  
Hui Ling Du ◽  
Ping Qi ◽  
Ai Min Liu
Keyword(s):  
Design Of Experiments ◽  
Orthogonal Experiment ◽  
Catalyst Activity ◽  
Sol Gel ◽  
Synthesis Conditions ◽  
Preparation Conditions ◽  
Photodegradation Efficiency ◽  
Nano Crystalline ◽  
Photocatalytic Activities ◽  
Four Levels

In the present study, design of experiments (Orthogonal experiment) was used to find an optimal combination for the factors, which affect the catalytic activity of nano-crystalline TiO2 powder synthesized by sol–gel method. Sixteen kinds of TiO2 powder were prepared by changing three material ratio at four levels. The effects of calcinations temperature on the catalyst activity of TiO2 were investigated by single factor experiments. TiO2 were characterized by XRD. The results of design of experiments are examined by the direct observation analysis. The preparation conditions have been optimized as material ratio nTi(OC4H9)4: nH2O: nHN(C2H5OH)2: nC2H5OH=1:2:2.5:20, mean 16.8 nm TiO2 nanoparticle with anatase structure obtained at 500°C calcination. The photodegradation efficiency of methylene blue in aqueous solution is 99 % under 1g/L catalyst.

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