CuO/CeO2 and CuO/PrO2-CeO2 Catalysts for Preferential Oxidation of CO

2013 ◽  
Vol 773 ◽  
pp. 601-605 ◽  
Author(s):  
Zhi Jun Zhao ◽  
Ruo Yu Wang ◽  
Qian Long Zhao ◽  
En Peng Wang ◽  
Hai Quan Su ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Hydrothermal Method ◽  
Surface Area ◽  
Pore Volume ◽  
Crucial Role ◽  
Textural Properties ◽  
Bet Surface Area ◽  
Oxidation Of Co ◽  
Preferential Oxidation Of Co ◽  
Adsorption Desorption

The CuO/CeO2and CuO/PrO2-CeO2catalysts were prepared by the hydrothermal method, and characterized via XRD, SEM and N2adsorption-desorption techniques. The study shows that the BET surface area and pore volume of the CuO/PrO2-CeO2catalysts increase with the increase of praseodymium content. The CuO/CeO2catalyst presents higher catalytic activity in compare with the CuO/PrO2-CeO2catalysts although the addition of praseodymium promotes textural properties of the CuO/CeO2catalysts, and it proves that the interaction of CuO and CeO2has a crucial role in CO-PROX.

scholarly journals Surface and Catalytic Properties of γ-Irradiated Cr2O3/Al2O3 Solids

1997 ◽  
Vol 15 (6) ◽  
pp. 465-476 ◽  
Author(s):  
G.A. El-Shobaky ◽  
A.M. Ghozza ◽  
G.M. Mohamed
Keyword(s):  
Catalytic Activity ◽  
Co Oxidation ◽  
Surface Area ◽  
Pore Volume ◽  
Active Sites ◽  
Catalytic Properties ◽  
Total Pore Volume ◽  
Bet Surface Area ◽  
Two Samples ◽  
Γ Rays

Two samples of Cr2O3/Al2O3 were prepared by mixing a known mass of finely powdered Al(OH)3 with a calculated amount of CrO3 solid followed by drying at 120°C and calcination at 400°C. The amounts of chromium oxide employed were 5.66 and 20 mol% Cr2O3, respectively. The calcined solid specimens were then treated with different doses of γ-rays (20–160 Mrad). The surface and catalytic properties of the different irradiated solids were investigated using nitrogen adsorption at −196°C and the catalysis of CO oxidation by O2 at 300–400°C. The results revealed that γ-rays brought about a slight decrease in the BET surface area, SBET (15%), and in the total pore volume, Vp (20%), of the adsorbent containing 5.66 mol% Cr2O3. The same treatment increased the total pore volume, Vp (36%), and the mean pore radius, r̄ (43%), of the other adsorbent sample without changing its BET surface area. The catalytic activities of both catalyst samples were found to increase as a function of dose, reaching a maximum value at 80–160 Mrad and 40 Mrad for the solids containing 5.66 and 20 mol% Cr2O3, respectively. The maximum increase in the catalytic activity measured at 300°C was 59% and 100% for the first and second catalyst samples, respectively. The induced effect of γ-irradiation on the catalytic activity was an increase in the concentration of catalytically active sites taking part in chemisorption and in the catalysis of CO oxidation by O2 without changing their energetic nature. This was achieved by a progressive removal of surface hydroxy groups during the irradiation process.

scholarly journals On the Gas Storage Properties of 3D Porous Carbons Derived from Hyper-Crosslinked Polymers

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 588 ◽  
Author(s):  
Giorgio Gatti ◽  
Mina Errahali ◽  
Lorenzo Tei ◽  
Maurizio Cossi ◽  
Leonardo Marchese
Keyword(s):  
Thermal Treatment ◽  
Surface Area ◽  
Pore Volume ◽  
Chemical Activation ◽  
Chemical Characterization ◽  
Total Pore Volume ◽  
Textural Properties ◽  
Gas Storage ◽  
Bet Surface Area ◽  
Porous Carbons

The preparation of porous carbons by post-synthesis treatment of hypercrosslinked polymers is described, with a careful physico-chemical characterization, to obtain new materials for gas storage and separation. Different procedures, based on chemical and thermal activations, are considered; they include thermal treatment at 380 °C, and chemical activation with KOH followed by thermal treatment at 750 or 800 °C; the resulting materials are carefully characterized in their structural and textural properties. The thermal treatment at temperature below decomposition (380 °C) maintains the polymer structure, removing the side-products of the polymerization entrapped in the pores and improving the textural properties. On the other hand, the carbonization leads to a different material, enhancing both surface area and total pore volume—the textural properties of the final porous carbons are affected by the activation procedure and by the starting polymer. Different chemical activation methods and temperatures lead to different carbons with BET surface area ranging between 2318 and 2975 m2/g and pore volume up to 1.30 cc/g. The wise choice of the carbonization treatment allows the final textural properties to be finely tuned by increasing either the narrow pore fraction or the micro- and mesoporous volume. High pressure gas adsorption measurements of methane, hydrogen, and carbon dioxide of the most promising material are investigated, and the storage capacity for methane is measured and discussed.

Studying the removal of CO2 on stratified ZnO prepared by hydro

2021 ◽  
Vol 10 (4) ◽  
pp. 69-74
Author(s):  
Minh Pham Quang ◽  
Chang-Ha Lee ◽  
Tuan Vu Anh
Keyword(s):  
Physicochemical Properties ◽  
Hydrothermal Method ◽  
Surface Area ◽  
Pore Volume ◽  
Desorption Isotherm ◽  
Co2 Removal ◽  
Gas Composition ◽  
Thermogravimetric Method ◽  
Removal Experiments ◽  
Adsorption Desorption

In this study, ZnO was synthesized by the simple hydrothermal method. The physicochemical properties of the materials were characterized by SEM, XRD, N adsorption/desorption isotherm methods. The CO2 removal experiments were conducted using the thermogravimetric method (TGA). The material has a stratified structure, with a surface area of 24.4 m2/g and a pore volume of 0.280 cm3/g. The influences of temperature, ZnO morphology, and feed gas composition were studied. Besides, the durability and applicability of the material were evaluated through repeated regeneration.

Hard-Templating Synthesis of Mesopours La1-xSrxMnO3+σ Perovskite and Catalysis Activity in CO Oxidation

2011 ◽  
Vol 306-307 ◽  
pp. 1342-1349 ◽  
Author(s):  
Xue Hui Huang ◽  
Ming Li
Keyword(s):  
Electron Microscopy ◽  
Catalytic Activity ◽  
Surface Area ◽  
Sol Gel ◽  
Oxidation Of Co ◽  
X Ray ◽  
Adsorption Desorption ◽  
Templating Synthesis ◽  
Scanning Electron ◽  
Hard Templating

La1-xSrxMnO3+σperovskite/ySBA-15(x=0, 0.1, 0.2, 0.3、y=0, 1, 2, 3) catalyzers were prepared by two different methods, which are the hard-templating and sol-gel methods. The catalysts were characterized by Fourier transform infrared spectroscopy(FTIR), scanning electron microscopy(SEM), energy-dispersive spectroscopy(EDS), X-ray fluorescence spectroscopy(XRD) and N2adsorption/desorption(BET). Their catalytic activity in the oxidation of CO was evaluated. BET and SEM results showed that the repeated template samples had higher surface area(143.7m2/g) and smaller particle size(18nm). The catalytic activity for CO reached the highest value when x=0.2 and y=2. The repeated template samples had higher activity than the sol-gel samples due to the higher surface area.

scholarly journals An Eco-Friendly Process for Removal of Lead from Aqueous Solution

2017 ◽  
Vol 11 (5) ◽  
pp. 47 ◽  
Author(s):  
Heman A. Smail ◽  
Kafia M. Shareef ◽  
Zainab H. Ramli
Keyword(s):  
Heavy Metal ◽  
Oxalic Acid ◽  
Surface Area ◽  
Pore Volume ◽  
Metal Ion ◽  
Adsorption Equilibrium ◽  
Total Pore Volume ◽  
Heavy Metal Ion ◽  
Bet Surface Area ◽  
Barley Husk

The adsorption of lead (Pb II) ion on different types of synthesized zeolite was investigated. The BET surface area, total pore volume & average pore size distribution of these synthesized zeolites were determined by adsorption isotherms for N2, the surface area & total pore volume of their sources were found by adsorption isothermN2.The adsorption equilibrium was measured after 24h at room temperature (RT) & concentration 10mg.L-1 of Pb (II) was used. The adsorption of heavy metal Pb (II) on four different prepared zeolites (LTA from Montmorillonite clay, FAU(Y)-B.H (G2) from Barley husk, Mordenite (G1) from Chert rock, FAU(X)-S.C (G3) from shale clay & modified Shale clay by oxalic acid (N1) & sodium hydroxide (N2)), were compared with the adsorption of their sources by using static batch experimental method. The major factors affecting the heavy metal ion sorption on different synthesized zeolites & their sources were investigated. The adsorption equilibrium capacity (Qm) of Pb (II) ion for different synthesized zeolites ordered from (N1>N2>LTA>G3>G2>G1&for their sources ordered Shale clay >Montmorilonite> Barley husk>Chert rock. The atomic absorption spectrometry was used for analysis of lead heavy metal ion, the obtained results in this study showed that the different synthesized zeolites were efficient ion exchanges for removing heavy metal, in particular, the modified zeolite from shale clay by oxalic acid.

Modulated synthesis and isoreticular expansion of Th-MOFs with record high pore volume and surface area for iodine adsorption

2020 ◽  
Vol 56 (49) ◽  
pp. 6715-6718 ◽  
Author(s):  
Zi-Jian Li ◽  
Yu Ju ◽  
Bowen Yu ◽  
Xiaoling Wu ◽  
Huangjie Lu ◽  
...  
Keyword(s):  
Single Crystals ◽  
Surface Area ◽  
Pore Volume ◽  
Bet Surface Area ◽  
Void Space ◽  
Adsorption Capacities ◽  
Iodine Adsorption

Isoreticular expansion of Th-MOFs via modulated synthesis yielded seven hierarchical complexes with superior quality single crystals, record high void space and BET surface area among Th materials, and exceptional iodine adsorption capacities.

Performance of Transition Metal Ions Exchanged Zeolite 13X in Greenhouse Gas Reduction

2007 ◽  
Author(s):  
K. S. Hui ◽  
Christopher Y. H. Chao ◽  
C. W. Kwong ◽  
M. P. Wan
Keyword(s):  
Activation Energy ◽  
Catalytic Activity ◽  
Transition Metal ◽  
Apparent Activation Energy ◽  
Surface Area ◽  
Active Sites ◽  
Methane Combustion ◽  
Bet Surface Area ◽  
Metal Loading ◽  
Zeolite 13X

This study investigated the performance of multi-transition metal (Cu, Cr, Ni and Co) ions exchanged zeolite 13X catalysts on methane emission abatement, especially at methane level of the exhaust from natural gas fueled vehicles. Catalytic activity of methane combustion using multi-ions exchanged catalyst was studied under different parameters: mole % of metal loading, inlet velocity and inlet methane concentration at atmospheric pressure and 500 °C. Performance of the catalysts was investigated and explained in terms of the apparent activation energy, number of active sites and BET surface area of the catalyst. This study showed that the multi-ions exchanged catalyst outperformed the single-ions exchanged and the acidified 13X catalysts. Lengthening the residence time could also lead to higher methane conversion %. Catalytic activity of the catalysts was influenced by the mole % of metal loading which played important roles in affecting the apparent activation energy of methane combustion, active sites and also the BET surface area of the catalyst. Increasing mole % of metal loading in the catalyst decreased the apparent activation energy for methane combustion and also the BET surface area of the catalyst. In view of these, there existed an optimized mole % of metal loading where the highest catalytic activity was observed.

Synthesis and Preparation of Al-MCM-41 Mesoporous Materials Using Oil Shale Residue

2019 ◽  
Vol 944 ◽  
pp. 1192-1198
Author(s):  
Rong Wang ◽  
Zhi Xiang Lin ◽  
Yang Zhao ◽  
Xiao Dong Xu ◽  
Yan Xi Deng
Keyword(s):  
Surface Area ◽  
Mesoporous Materials ◽  
Pore Volume ◽  
Oil Shale ◽  
Bet Surface Area ◽  
Ammonium Bromide ◽  
Scale Production ◽  
Scanning Electron Micrographs ◽  
One Step ◽  
Mcm 41

An Al-supported cage-like mesoporous silica type MCM-41 has been prepared using a simple one-step synthetic procedure using oil shale residue and CTAB(Hexadecyl trimethyl Ammonium Bromide) as the template. The effects of temperature on the porosity, structure and surface area of Al-MCM-41 mesoporous materials were characterized by X-ray powder diffraction, N2adsorption desorption, scanning electron micrographs (SEM), transmission electron microscopy (TEM) techniques and Fourier transform infrared spectroscopy (FT-IR). The results indicated that temperature was a key to the characteristics of Al-MCM-41 materials, and when the temperature up to 333 K, Al-MCM-41 exhibited excellent characteristics with high degree of order, high surface area and pore volume. The one-step hydrothermal synthesized MCM-41 mesoporous material possessed high BET surface area, high pore size and high pore volume. They are respectively 835.1 m2/g, 32.6 Å and 1.22 cm3/g under the condition of the Si : Al =78:1, pH =10, crystallization temperature was 333K, crystallization time was 48h and calcination at 823 K for 5 h in air. All the results indicated the possibility of using oil shale residue as silicon and aluminum source to produce Al-MCM-41, and gave us a new way to recycle a solid waste. As well as this made it impossible to large-scale production of Al-MCM-41. Keywords: Al-MCM-41 mesoporous materials, oil shale residue, one-step synthesis

scholarly journals Phenol adsorption on high microporous activated carbons prepared from oily sludge: equilibrium, kinetic and thermodynamic studies

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
N. Mojoudi ◽  
N. Mirghaffari ◽  
M. Soleimani ◽  
H. Shariatmadari ◽  
C. Belver ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Pore Volume ◽  
Activated Carbons ◽  
Ph Value ◽  
Chemical Activation ◽  
Bet Surface Area ◽  
Polluted Water ◽  
Oily Sludge ◽  
Maximum Adsorption Capacity ◽  
Adsorption Desorption

AbstractThe purpose of this study was the preparation, characterization and application of high-performance activated carbons (ACs) derived from oily sludge through chemical activation by KOH. The produced ACs were characterized using iodine number, N2 adsorption-desorption, Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The activated carbon prepared under optimum conditions showed a predominantly microporous structure with a BET surface area of 2263 m2 g−1, a total pore volume of 1.37 cm3 g−1 and a micro pore volume of 1.004 cm3 g−1. The kinetics and equilibrium adsorption data of phenol fitted well to the pseudo second order model (R2 = 0.99) and Freundlich isotherm (R2 = 0.99), respectively. The maximum adsorption capacity based on the Langmuir model (434 mg g−1) with a relatively fast adsorption rate (equilibrium time of 30 min) was achieved under an optimum pH value of 6.0. Thermodynamic parameters were negative and showed that adsorption of phenol onto the activated carbon was feasible, spontaneous and exothermic. Desorption of phenol from the adsorbent using 0.1 M NaOH was about 87.8% in the first adsorption/desorption cycle and did not decrease significantly after three cycles. Overall, the synthesized activated carbon from oily sludge could be a promising adsorbent for the removal of phenol from polluted water.

scholarly journals Pembuatan Katalis Pd-Ce/γ –Al2O3 dan Uji Aktivitas terhadap Oksidasi Metana

1999 ◽  
Vol 2 (3) ◽  
pp. 104-111
Author(s):  
Ahmad Suseno ◽  
Triyono Triyono ◽  
Bambang Setiaji
Keyword(s):  
Catalytic Activity ◽  
Surface Area ◽  
Pore Volume ◽  
Pore Radius ◽  
Flow Reactor ◽  
Chloride Salt ◽  
Oxidation Of Methane ◽  
Sorption Method ◽  
Determine Surface Area ◽  
Products Of Reaction

Effects of Ce addition on Pt/γ - Al2O3 catalysts preparation and their catalytic activity on oxidation of methane have been investigated. In this study, the catalysts were prepared by impregnating chloride salt solution of palladium and sulphate salt of cerium on γ-AI2O3 support. Characterization of catalysts was conducted by gas sorption method to determine surface area, pore radius and pore volume. The test of catalytic activity on oxidation of methane was carried out in a flow reactor system at a temperature range from 350°C to 600°C. Products of reaction were analysed by non-dispersive IR spectroscopy. It was observed that the surface area, pore radius and pore volume decrease with the addition of cerium. The results of oxidation process showed that Pd-Ce/γ-Al2O3 catalyst can be used for oxidation of methane up to 90.62% conversion

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