scholarly journals Catalytic activities for the complete oxidation of toluene over MnO2, Co3O4 and NiO catalysts

2020 ◽  
Vol 9 (1) ◽  
pp. 88-94
Author(s):  
Tuan Nguyen Dinh Minh ◽  
Nga Phan Thi Hang
Keyword(s):  
Transition Metal Oxides ◽  
Complete Oxidation ◽  
X Ray Diffraction ◽  
Total Oxidation ◽  
X Ray ◽  
Catalytic Activities ◽  
Isotherm Adsorption ◽  
Adsorption Desorption ◽  
Scanning Electron ◽  
Catalytic Performances

In this study, the catalytic performances of the complete oxidation of toluene over different transition metal oxides including MnO2, Co3O4 and NiO were investigated. These oxides were synthesized by hydrothermal method, followed by annealing. The catalysts were characterized by X-ray diffraction (XRD), Scanning Electron Microscope (SEM) and Nitrogen isotherm adsorption-desorption before being evaluated their catalytic activity for the total oxidation of toluene in air. As a result, MnO2 was illustrated as the best catalyst having largest surface area and lowest activation energy, followed by Co3O4 and NiO.

Mesoporous Sulfur-Doped TiO2 Microspheres for Catalytic Degradation of Methylene Blue under Visible Light

2015 ◽  
Vol 1118 ◽  
pp. 242-250 ◽  
Author(s):  
Zhen Wu Ding ◽  
Si Chen ◽  
Zhong Qing Liu ◽  
Cheng Fa Jiang ◽  
Wei Chu
Keyword(s):  
Methylene Blue ◽  
Visible Light ◽  
Diffuse Reflectance ◽  
Visible Region ◽  
Catalytic Degradation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Adsorption Desorption ◽  
Scanning Electron ◽  
Catalytic Performances

Mesoporous S-doped TiO2 microspheres were synthesized via hydrothermal method using Ti (SO4)2 precursor and urea as homogeneous precipitate agent. The TiO2-based catalyst samples were characterized by means of Field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), N2 adsorption/desorption and UV-vis diffuse reflectance spectra (UV-vis DRS). Photo-catalytic experiments were carried out by catalytic degradation of methylene blue aqueous solution under visible light. It was found that the S-doped TiO2 microspheres gave better photo-catalytic performances. The higher absorbance in the visible region explained this phenomenon. There was an appropriate Ti (SO4)2 amount for the catalyst with better photo-catalytic degradation.

Photocatalytic activity of TiO2 synthesized by anodization and anodic spark deposition

MRS Advances ◽  
2020 ◽  
Vol 5 (61) ◽  
pp. 3141-3152
Author(s):  
Alma C. Chávez-Mejía ◽  
Génesis Villegas-Suárez ◽  
Paloma I. Zaragoza-Sánchez ◽  
Rafael Magaña-López ◽  
Julio C. Morales-Mejía ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Surface Characteristics ◽  
Amorphous Solids ◽  
X Ray Diffraction ◽  
X Ray ◽  
Catalytic Activities ◽  
Anodic Spark Oxidation ◽  
Porous Surfaces ◽  
Scanning Electron

AbstractSeveral photocatalysts, based on titanium dioxide, were synthesized by spark anodization techniques and anodic spark oxidation. Photocatalytic activity was determined by methylene blue oxidation and the catalytic activities of the catalysts were evaluated after 70 hours of reaction. Scanning Electron Microscopy and X Ray Diffraction analysis were used to characterize the catalysts. The photocatalyst prepared with a solution of sulfuric acid and 100 V presented the best performance in terms of oxidation of the dye (62%). The electric potential during the synthesis (10 V, low potential; 100 V, high potential) affected the surface characteristics: under low potential, catalyst presented smooth and homogeneous surfaces with spots (high TiO2 concentration) of amorphous solids; under low potential, catalyst presented porous surfaces with crystalline solids homogeneously distributed.

Preparation and Characterization TiO2 Aerogel Fibers

2013 ◽  
Vol 743-744 ◽  
pp. 434-437
Author(s):  
Miao Lv ◽  
Guo Tong Qin ◽  
Wei Wei
Keyword(s):  
Electron Microscopy ◽  
Pore Diameter ◽  
Supercritical Drying ◽  
Mass Ratio ◽  
Composite Fibers ◽  
X Ray Diffraction ◽  
Average Pore ◽  
X Ray ◽  
Adsorption Desorption ◽  
Scanning Electron

TiO2aerogel fibers have been fabricated by electron span combined supercritical drying technique. Polyvinylpyrrolidone (PVP)/TiO2composite fibers are prepared by electrospinning PVP and TiO2precursor Ti (OC4H9)4. TiO2aerogel fibers are obtained by supercritical drying PVP/TiO2composite fibers using ethanol as media. Structural of the aerogel fibers was investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD) and N2adsorption at 77 K. The effect of mass ratio of PVP/TiO2was investigated. SEM shows that pore structure of nanofibers was well developed, with the diameter of nanofibers about 2 μm. N2adsorption/desorption data show that the highest surface area of aerogel fibers reached 241.6 m2/g with the average pore diameter about 10 nm. The aerogel fibers were anatase type TiO2.

scholarly journals The Production of Green Diesel Rich Pentadecane (C15) from Catalytic Hydrodeoxygenation of Waste Cooking Oil using Ni/Al2O3-ZrO2 and Ni/SiO2-ZrO2

2021 ◽  
Vol 17 (1) ◽  
pp. 135-145
Author(s):  
Momodou Salieu Sowe ◽  
Arda Rista Lestari ◽  
Eka Novitasari ◽  
Masruri Masruri ◽  
Siti Mariyah Ulfa
Keyword(s):  
Batch Reactor ◽  
Waste Cooking Oil ◽  
Gas Chromatography Mass Spectrometry ◽  
X Ray Diffraction ◽  
Fuel Processing ◽  
Green Diesel ◽  
X Ray ◽  
Cooking Oil ◽  
Isotherm Adsorption ◽  
Adsorption Desorption

Hydrodeoxygenation (HDO) is applied in fuel processing technology to convert bio-oils to green diesel with metal-based catalysts. The major challenges to this process are feedstock, catalyst preparation, and the production of oxygen-free diesel fuel. In this study, we aimed to synthesize Ni catalysts supported on silica-zirconia and alumina-zirconia binary oxides and evaluated their catalytic activity for waste cooking oil (WCO) hydrodeoxygenation to green diesel. Ni/Al2O3-ZrO2 and Ni/SiO2-ZrO2 were synthesized by wet-impregnation and hydrodeoxygenation of WCO was done using a modified batch reactor. The catalysts were characterized using X-ray diffraction (XRD), X-ray fluorescence (XRF), and scanning electron microscopy - energy dispersive X-ray spectroscopy (SEM-EDS), and N2 isotherm adsorption-desorption analysis. Gas chromatography - mass spectrometry (GC-MS) analysis showed the formation of hydrocarbon framework n-C15 generated from the use of Ni/Al2O3-ZrO2 with the selectivity of 68.97% after a 2 h reaction. Prolonged reaction into 4 h, decreased the selectivity to 58.69%. Ni/SiO2-ZrO2 catalyst at 2 h showed selectivity of 55.39% to n-C15. Conversely, it was observed that the reaction for 4 h increased selectivity to 65.13%. Overall, Ni/Al2O3-ZrO2 and Ni/SiO2-ZrO2 catalysts produced oxygen-free green diesel range (n-C14-C18) enriched with n-C15 hydrocarbon. Reaction time influenced the selectivity to n-C15 hydrocarbon. Both catalysts showed promising hydrodeoxygenation activity via the hydrodecarboxylation pathway. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0). 

scholarly journals Synthesis of porous LaFeO3 prepared by nanocasting method for photo-Fenton degradation of oily-containing wastewater

2021 ◽  
Vol 11 (1) ◽  
pp. xx-xx
Author(s):  
Nga Phan To ◽  
Lien Nguyen Hong ◽  
Tuyen Le Van ◽  
Nhan Phan Chi ◽  
Huyen Phan Thanh
Keyword(s):  
Electron Microscopy ◽  
Catalytic Activity ◽  
Visible Light ◽  
Diffuse Reflectance Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Catalytic Activities ◽  
Transmission Electron ◽  
Visible Light Driven ◽  
Adsorption Desorption

Porous LaFeO3 were synthesised by nanocasting method using mesoporous silica (SBA-15) as a hard template and used as a visible-light-driven photocatalyst. The as-synthesised LaFeO3 photocatalyst were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray Diffraction (XRD), N2 adsorption-desorption, and Ultraviolet–Visible Diffuse Reflectance Spectroscopy (UV-vis DRS). The photo-Fenton catalytic activities of porous LaFeO3 were investigated for the degradation of oily-containing wastewater. The results showed that porous LaFeO3 had better photo-Fenton catalytic activity under visilbe light irradiation than pure LaFeO3. The remarkable improvement photo-Fenton catalytic activity of porous LaFeO3 material could be attributed to the synergistic effect of adsorption and visible light photo-Fenton processes thanks to its porous structure.

scholarly journals Effect of Pretreatment with Sulfuric Acid on Catalytic Hydrocracking of Fe/AC Catalysts

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Ruiyu Wang ◽  
Fei Wang ◽  
Ling Liu
Keyword(s):  
Hydrogen Pressure ◽  
Bituminous Coal ◽  
Model Compound ◽  
Synergetic Effect ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Initial Hydrogen Pressure ◽  
Adsorption Desorption ◽  
Scanning Electron

Activated carbon (AC) was modified by H2SO4 and used as a support for catalyst. The Fe2S3/AC-T catalyst was prepared by deposition-precipitation method and used to catalyze hydrocracking of coal-related model compound, di(1-naphthyl)methane (DNM). The properties of catalyst were studied by N2 adsorption-desorption, X-ray diffraction, and scanning electron microscopy. The result showed that ferric sulfate and acidic centers had synergetic effect on hydrocracking of DNM when using Fe2S3/AC-T as catalyst, the optimal loading of Fe is 9 wt.%. Hydroconversion of the extraction residue from Guizhou bituminous coal was also studied using Fe2S3/AC-T as the catalyst. The reaction was conducted in cyclohexane under 0.8 Mpa of initial hydrogen pressure at 310°C. The reaction mixture was extracted with petroleum ether and analyzed by GC/MS. Amounts of organic compounds which fall into the categories of homologues of benzene and naphthalene were detected. It suggested that the catalyst could effectively catalyze the cleavage of C-C-bridged bonds.

Biosorption of crystal violet dye using inactive biomass of the fungus Diaporthe schini

2019 ◽  
Vol 79 (4) ◽  
pp. 709-717 ◽  
Author(s):  
Patrícia Grassi ◽  
Caroline Reis ◽  
Fernanda C. Drumm ◽  
Jordana Georgin ◽  
Denise Tonato ◽  
...  
Keyword(s):  
Crystal Violet ◽  
X Ray Diffraction ◽  
N2 Adsorption ◽  
Biosorption Capacity ◽  
X Ray ◽  
Crystal Violet Dye ◽  
Endothermic Process ◽  
Desorption Isotherms ◽  
Adsorption Desorption ◽  
Scanning Electron

Abstract An inactive biomass of a new fungus recently discovered, Diaporthe schini, was evaluated for the biosorption of crystal violet (CV) in simulated textile effluents. The characterization assays were performed using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and N2 adsorption/desorption isotherms. The influences of pH and biosorbent dosage on the biosorption capacity were evaluated. Kinetics, equilibrium and thermodynamic studies were also carried out. Characterization techniques showed an amorphous biosorbent, with a rough surface containing irregular particles and surface area of 6.5 m2 g−1. The most adequate values of pH and biosorbent dosage were 7.5 and 0.4 g L−1, respectively. The Elovich kinetic model and the Sips equilibrium model were suitable to fit the experimental data. The biosorption capacity increased with temperature, reaching a maximum biosorption capacity of 642.3 mg g−1 at 328 K. The biosorption was a spontaneous and endothermic process. Diaporthe schini inactive biomass was an interesting biosorbent to treat colored effluents, presenting efficiency of 87% in the decolorization of a simulated dye house effluent.

Mesoporous TiO2 Prepared by Using Lac Red as Template：Synthesis, Characterization, and Adsorption of Gaseous Acetaldehyde

2013 ◽  
Vol 742 ◽  
pp. 448-451
Author(s):  
Ming Feng Wang ◽  
Tou Gen Liao ◽  
Bao Kun Zhu ◽  
Yao Wang ◽  
Yan Qing Duan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Mesoporous Titania ◽  
X Ray Diffraction ◽  
High Adsorption ◽  
X Ray ◽  
Transmission Electron ◽  
Adsorption Desorption ◽  
Scanning Electron

Mesoporous TiO2 with anatase crystalline structure (MTiO2) has been synthesized by using Lac Red as template. The synthesized mesoporous titania samples were characterized by a combination of various physicochemical techniques, such as X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), N2 adsorption/desorption. It was found that without any external doping MTiO2 exhibited significant high adsorption abilities for adsorbing the gaseous acetaldehyde by the adsorption ratio of 39.15%.

Effect of Co Doping on the Properties of Ce0.75Zr0.25O2 Nanocatalyst

2014 ◽  
Vol 575 ◽  
pp. 93-96 ◽  
Author(s):  
S. Hanim Md Nor ◽  
M. Nazri Abu Shah ◽  
Abdul Hadi ◽  
Kamariah Noor Ismail
Keyword(s):  
Particle Distribution ◽  
Preparation Method ◽  
Precipitation Method ◽  
Ammonium Bromide ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co Doping ◽  
Adsorption Desorption ◽  
Scanning Electron ◽  
Structure Properties

5wt% Co deposited on a support catalyst Ce0.75Zr0.25O2 mixed oxide were prepared by combination of microemulsion and deposition-precipitation method followed by calcinations at temperature 500°C. The microemulsion component comprise of cetyl trimetyl ammonium-bromide (CTAB), 1-butanol, n-octane and aqueous solution. Sodium hydroxide (NaOH) was used as precipitation precursor for the preparation of water-in-oil microemulsions method. The particles were characterized by X-ray diffraction (XRD), N2 adsorption-desorption analysis and Field Emission Scanning Electron Microscopy (FESEM). The results showed the preparation method has significant influences on the textural and structure properties of Co/Ce0.75Zr0.25O2. The formation of Co/Ce0.75Zr0.25O2 inhibit the better performance based on the particles size, specific surface area and particle distribution of cobalt into Ce0.75Zr0.25O2.

scholarly journals The catalytic performances of α-MnO2 and δ-MnO2 catalysts synthesized from KMnO4 and ethanol for total oxidation of isopropanol

2020 ◽  
Vol 9 (1) ◽  
pp. 53-59
Author(s):  
Tuan Nguyen Dinh Minh ◽  
Nga Phan Thi Hang
Keyword(s):  
Low Temperature ◽  
Temperature Programmed Reduction ◽  
Total Oxidation ◽  
Isothermal Adsorption ◽  
Catalytic Activities ◽  
Oxidation Reduction ◽  
Higher Temperature ◽  
Temperature Programmed ◽  
Adsorption Desorption ◽  
Catalytic Performances

In this study, the catalytic activities of total oxidation of isopropanol (IPA) over MnO2-based catalysts (α-MnO2 and δ-MnO2) were studied and compared. These catalysts were synthesized by an oxidation/reduction route between ethanol and KMnO4 by using dropwise method. Their morphological, structural properties, specific surface area, pore distribution and reducibility were characterized by SEM, XRD, FTIR, N2 isothermal adsorption-desorption, and hydrogen temperature-programmed reduction (H2-TPR). As a result, IPA was significantly oxidized to acetone at low temperature (130 °C) and subsequently to CO2 at higher temperature. α-MnO2 was demonstrated as a better catalyst for total oxidation of IPA compared with δ-MnO2. Over 205 °C, IPA was completely oxidized to CO2. Additionally, the high reducibility of δ-MnO2 was found to be correlated with higher activity of IPA toward acetone at low temperature.

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