scholarly journals The Influence of Precursor on the Preparation of CeO2 Catalysts for the Total Oxidation of the Volatile Organic Compound Propane

Catalysts ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1461
Author(s):  
Kieran Aggett ◽  
Thomas E. Davies ◽  
David J. Morgan ◽  
Dan Hewes ◽  
Stuart H. Taylor
Keyword(s):  
Catalytic Activity ◽  
Surface Area ◽  
Active Oxygen Species ◽  
Catalyst Activity ◽  
Precipitation Method ◽  
Oxygen Species ◽  
Total Oxidation ◽  
Volatile Organic ◽  
Predominant Factor ◽  
Enhanced Surface

CeO2 catalysts were prepared by a precipitation method using either (NH4)2Ce(NO3)6 or Ce(NO3)3, as CeIV or CeIII precursors respectively. The influence of the different precursors on catalytic activity was evaluated for the total oxidation of propane with water present in the feed. The catalyst prepared using the CeIV precursor was more active for propane total oxidation. The choice of precursor influenced catalyst properties such as surface area, reducibility, morphology, and active oxygen species. The predominant factor associated with the catalytic activity was related to the formation of either CeO2.nH2O or Ce2(OH)2(CO3)2.H2O precipitate species, formed prior to calcination. The formation of CeO2.nH2O resulted in enhanced surface area which was an important factor for controlling catalyst activity.

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

Clay Minerals ◽  
2015 ◽  
Vol 50 (2) ◽  
pp. 211-219 ◽  
Author(s):  
Bo Xue ◽  
Hongmei Guo ◽  
Lujie Liu ◽  
Min Chen
Keyword(s):  
Catalytic Activity ◽  
Ethyl Acetate ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Active Sites ◽  
Industrial Applications ◽  
High Catalytic Activity ◽  
Total Oxidation ◽  
Pillared Montmorillonite

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.

TAP study on the active oxygen species in the total oxidation of propane over a CuO–CeO2/γ-Al2O3 catalyst

2010 ◽  
Vol 157 (1-4) ◽  
pp. 49-54 ◽  
Author(s):  
V. Balcaen ◽  
R. Roelant ◽  
H. Poelman ◽  
D. Poelman ◽  
G.B. Marin
Keyword(s):  
Active Oxygen Species ◽  
Active Oxygen ◽  
Oxygen Species ◽  
Total Oxidation ◽  
Al2o3 Catalyst

Fibrous MnO2 Nanoparticles with (2 × 2) Tunnel Structures. Catalytic Activity in the Total Oxidation of Volatile Organic Compounds

2009 ◽  
Vol 9 (6) ◽  
pp. 3837-3842 ◽  
Author(s):  
M. I. Domínguez ◽  
P. Navarro ◽  
F. Romero-Sarria ◽  
D. Frías ◽  
S. A. Cruz ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Total Oxidation ◽  
Volatile Organic

scholarly journals The enzyme-like catalytic activity of cerium oxide nanoparticles and its dependency on Ce3+ surface area concentration

Nanoscale ◽  
2018 ◽  
Vol 10 (15) ◽  
pp. 6971-6980 ◽  
Author(s):  
V. Baldim ◽  
F. Bedioui ◽  
N. Mignet ◽  
I. Margaill ◽  
J.-F. Berret
Keyword(s):  
Reactive Oxygen Species ◽  
Hydrogen Peroxide ◽  
Catalytic Activity ◽  
Surface Area ◽  
Cerium Oxide ◽  
Superoxide Radical ◽  
Cerium Oxide Nanoparticles ◽  
Oxide Nanoparticles ◽  
Oxygen Species ◽  
Surface Area Concentration

Cerium oxide nanoparticles are known to catalyze the decomposition of reactive oxygen species such as the superoxide radical and hydrogen peroxide.

Magnetic Spinel Ferrite: An Efficient, Reusable Nano Catalyst for HMFSynthesis

2021 ◽  
Vol 10 ◽  
Author(s):  
Jyoti Dhariwal ◽  
Ravina Yadav ◽  
Sheetal Yadav ◽  
Anshu Kumar Sinha ◽  
Chandra Mohan Srivastava ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Surface Area ◽  
Heterogeneous Catalysts ◽  
Spinel Ferrite ◽  
Active Surface ◽  
Catalytic Performance ◽  
Ferrite Nanoparticles ◽  
Precipitation Method ◽  
Magnetic Characteristics ◽  
Nano Catalyst

Aim: In the present work, the preparation and catalytic activity of spinel ferrite [MFe2O4; M = Fe, Mn, Co, Cu, Ni] nanoparticles to synthesize 5-hydroxymethylfurfural (HMF) have been discussed. Background: Ferrites possess unique physicochemical properties, including excellent magnetic characteristics, high specific surface area, active surface sites, high chemical stability, tunable shape and size, and easy functionalization. These properties make them essential heterogeneous catalysts in many organic reactions. Objective: This study aims to synthesize a series of transition metal ferrite nanoparticles and use them in the dehydration of carbohydrates for 5-hydroxymethylfurfural (HMF) synthesis. Method: The ferrite nanoparticles were prepared via the co-precipitation method, and PXRD confirmed their phase stability. The surface area and the crystallite size of the nanoparticles were calculated using BET and PXRD, respectively. Result: The easily prepared heterogeneous nanocatalyst showed a significant catalytic performance, and among all spinel ferrites, CuFe2O4 revealed maximum catalytic ability. Conclusion: Being a heterogeneous catalyst and magnetic in nature, ferrite nanoparticles were easily recovered by using an external magnet and reused up to several runs without substantial loss in catalytic activity. Others: HMF was synthesized from fructose in a good yield of 71%.

Calcined Ni—Al layered double hydroxide as a catalyst for total oxidation of volatile organic compounds: Effect of precursor crystallinity

2007 ◽  
Vol 61 (2) ◽  
Author(s):  
Z. Mikulová ◽  
P. Čuba ◽  
J. Balabánová ◽  
T. Rojka ◽  
F. Kovanda ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Hydrothermal Treatment ◽  
Layered Double Hydroxide ◽  
Mixed Oxides ◽  
Slight Effect ◽  
Total Oxidation ◽  
Volatile Organic ◽  
Double Hydroxide ◽  
Short Time ◽  
Oxidation Of Ethanol

AbstractThe effect of hydrothermal treatment on properties (crystallinity, porous structure, reducibility, acidity, basicity, and catalytic activity and selectivity in toluene and ethanol total oxidation) of Ni—Al layered double hydroxide precursors and related mixed oxides was examined. The hydrothermal treatment increased considerably both the content of crystalline phase and LDH crystallite size. On the other hand, only a slight effect of the precursor hydrothermal treatment on crystallinity of the related Ni—Al mixed oxides obtained by calcination at 450°C was observed. The reducibility of NiO particles appeared to be hindered considerably compared to the reducibility of pure NiO. Catalytic activity of the Ni—Al mixed oxides prepared from the precursors hydrothermally treated for a short time (4 h) was the highest. The highest amount of acetaldehyde formed during the total oxidation of ethanol, i.e. the worst selectivity was found for the calcined Ni—Al LDH without hydrothermal treatment.

scholarly journals Catalytic Activity of Cr2O3/sepiolite in the oxidation of benzyl alcohol

2018 ◽  
Vol 56 (3) ◽  
pp. 295
Author(s):  
Nguyen Tien Thao ◽  
Nguyen Thi Nhu ◽  
Ngo Thi Thuan
Keyword(s):  
Catalytic Activity ◽  
Reaction Time ◽  
Benzyl Alcohol ◽  
Surface Area ◽  
Active Sites ◽  
Large Surface Area ◽  
Precipitation Method ◽  
Chromium Oxides ◽  
Physical Methods ◽  
Oxidation Of Benzyl Alcohol

Cr2O3/sepiolite samples with different loadings have been prepared through the precipitation method and characterized by several physical methods such as XRD, TEM, BET, and TGA... The as-prepared materials have large surface area, high distribution of Cr2O3 nanoxides on the nanofibrous sepiolite. The catalysts have been tested in the oxidation of benzyl alcohol with t-BuOOH. Chromium oxides were found to be active sites for the oxidation of benzyl alcohol to aldehyde. The catalytic activity varied with reaction time and temperature. The appropriate temperature is about 60-70oC with conversion of 40-60% and benzaldehyde selectivity of 90%.

scholarly journals PREPARATION OF INORGANIC CATALYST BASED HEMATITE (-Fe2O3) COMPOUND EXTRACTED FROM ACEH IRON ORE MINERAL AND ITS CATALYTIC ACTIVITY ON TRANSESTERIFICATION OF COCONUT OIL

2019 ◽  
Vol 19 (1) ◽  
pp. 24-29 ◽  
Author(s):  
Muliadi Ramli ◽  
Anneza Astriet ◽  
T. Banta Darmawan ◽  
Saiful Saiful ◽  
Susilawati Susilawati ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Surface Area ◽  
Iron Ore ◽  
Methyl Esters ◽  
Coconut Oil ◽  
Precipitation Method ◽  
Chemical Agent ◽  
Low Concentration ◽  
Sodium Metal ◽  
Hematite Fe2o3

Hematite (Fe2O3) was successfully extracted from the Aceh iron ore mineral by precipitation method with employing sulphuricacid (H2SO4) as chemical agent.  Furthermore, the extracted hematite was modified with sodium metal (K), namely it doped with NaOH of 5% and 10% (w/w), respectively. Based on the characterization results using XRD and SEM- EDS proved that modified catalyst (Na2O/Fe2O3) with their homogeneous size were resulted while the hematite (Fe2O3) particles was dopped withNaOH at its low concentration of (5% wt/wt), however while doping with the higher concentration of NaOH (10% w/w), agglomeration was taken place among the catalyst particles in which decreasing the surface area of the modified catalysts. Finally, the modified catalyst (Na2O/Fe2O3) was successfully applied as an inorganic catalyst on transesterification of coconut oil and methanol (T = 55 – 60oC, 2 h)for forming methyl esters asbiodiesel compounds. 

scholarly journals Eco-Friendly Cavity-Containing Iron Oxides Prepared by Mild Routes as Very Efficient Catalysts for the Total Oxidation of VOCs

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1387 ◽  
Author(s):  
Rut Sanchis ◽  
Daniel Alonso-Domínguez ◽  
Ana Dejoz ◽  
María Pico ◽  
Inmaculada Álvarez-Serrano ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Surface Area ◽  
Iron Oxides ◽  
Photoelectron Spectroscopy ◽  
Specific Activity ◽  
High Surface ◽  
Superior Performance ◽  
Porous Iron ◽  
Total Oxidation ◽  
X Ray

Iron oxides (FeOx) are non-toxic, non-expensive and environmentally friendly compounds, which makes them good candidates for many industrial applications, among them catalysis. In the present article five catalysts based on FeOx were synthesized by mild routes: hydrothermal in subcritical and supercritical conditions (Fe-HT, Few200, Few450) and solvothermal (Fe-ST1 and Fe-ST2). The catalytic activity of these catalysts was studied for the total oxidation of toluene using very demanding conditions with high space velocities and including water and CO2 in the feed. The samples were characterized by X-ray diffraction (XRD), scanning and high-resolution transmission electron microscopy (SEM and HRTEM), X-ray photoelectron spectroscopy (XPS) and nitrogen adsorption-desorption isotherms. It was observed that the most active catalyst was a cavity-containing porous sample prepared by a solvothermal method with a relatively high surface area (55 m2 g−1) and constituted by flower-like aggregates with open cavities at the catalyst surface. This catalyst displayed superior performance (100% of toluene conversion at 325 °C using highly demanding conditions) and this performance can be maintained for several catalytic cycles. Interestingly, the porous iron oxides present not only a higher catalytic activity than the non-porous but also a higher specific activity per surface area. The high activity of this catalyst has been related to the possible synergistic effect of compositional, structural and microstructural features emphasizing the role of the surface area, the crystalline phase present, and the properties of the surface.

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