Preparation, Characterization and Catalytic Activity of Sulfated Zirconia by Varied Sol-Gel Method

2015 ◽  
Vol 1123 ◽  
pp. 96-99
Author(s):  
Is Fatimah ◽  
Zulfa Zuhrufa
Keyword(s):  
Catalytic Activity ◽  
Surface Area ◽  
Sulfated Zirconia ◽  
Sol Gel ◽  
Acid Catalyst ◽  
Bet Surface Area ◽  
Ammonium Bromide ◽  
Templating Method ◽  
Prepared Material ◽  
Sol Gel Synthesis

The sulfated zirconia catalysts were was prepared by sol–gel processes consist of varied templating method. Both preparations consist of sol-gel synthesis of zirconium dioxide followed by sulfatation process by using NH4SO4solid reaction method. Two different templating agent; urea and cetyltrimetyl ammonium bromide was used in sol-gel processes. The prepared material was characterized using scanning electron microscope (SEM), x-ray diffraction (XRD) and Brunauer–Emmett–Teller (BET) measurements. From the XRD measurement it can be concluded that both materials consist of ZrO2in combined phases while from BET surface area analysis it can be noted that material prepared by urea template has higher specific surface area compared to that use CTAB template. Both materials exhibit the activity as acid catalyst in microwave assisted conversion of citronellal. It is also confirmed that the higher the surface area the higher total conversion of citronellal obtained. Study on the correlation between physicochemical properties of materials with the catalytic activity was discussed in this paper.

scholarly journals Magnetic Nanoparticles based on Natural Silica as a Methyl Ester Forming Acid Catalyst

2021 ◽  
Vol 23 (2) ◽  
pp. 49-54
Author(s):  
Falah Azizah Elmaria ◽  
S. N. Aisyiyah Jenie
Keyword(s):  
Magnetic Properties ◽  
Methyl Ester ◽  
Surface Area ◽  
Methyl Esters ◽  
Sol Gel ◽  
Acid Catalyst ◽  
Reaction Process ◽  
Bet Surface Area ◽  
Gas Chromatography Mass Spectrometry ◽  
Ammonium Bromide

Natural silica has advantages in various fields such as catalysts, because it is easily obtained and applied in the chemical reaction process. The synthesis of natural silica-based magnetic acid catalyst, MSNP/SO42- aims to obtain a large yield from the reaction process between oleic acid and methanol to form methyl ester. Natural silica obtained from geothermal waste was washed with distilled water, then sol gel method was applied at  pH of 4-6 to obtain SiO2 nanoparticles. FeCl3 was added to achieve the magnetic properties, and the cetyl trimethyl ammonium bromide  (CTAB) is varied in order to attain optimal mesoporous size. Brunauer emmet teller (BET) results showed optimum results from 1: 2 molarity ratio between silica and CTAB with a surface area of 520.94 m2/g. The acidic properties were obtained by immersion using H2SO4 0.5 M. The catalyst were tested for the acidic and magnetic properties  using temperature programmed desorption ammonia (TPD-NH3) and vibrating sample magnetometer (VSM) characterization resulting intotal acidity of 0.2488 mmol/g and. softmagnetic type, respectively. The BET surface area  of the sulfate modified into MSNP/SO42-, was decreased by 114.44 m2/g. Application of MSNP/SO42- as a catalyst for forming methyl esters obtained a percentage of 85.41% yield based on the gas chromatography mass spectrometry (GC- MS) results.

One-pot sol-gel synthesis of sulfated ZrO2-SiO2 catalysts for alcohol dehydration

2001 ◽  
Vol 79 (8) ◽  
pp. 1220-1223 ◽  
Author(s):  
Quan Zhuang ◽  
Jack M Miller
Keyword(s):  
Ammonium Sulfate ◽  
Sulfated Zirconia ◽  
Sol Gel ◽  
Synthesis Method ◽  
Acid Catalyst ◽  
Alcohol Dehydration ◽  
One Pot ◽  
Zirconium Propoxide ◽  
The One ◽  
Sol Gel Synthesis

Sulfated ZrO2–SiO2 catalysts were synthesized by one-pot sol-gel method using ammonium sulfate, zirconium propoxide, and tetraethyl orthosilicate as precursors. The catalysts were characterized by N2 adsorption and DRIFTS. On calcining the gel at elevated temperature, the ammonium sulfate decomposed, giving a sulfated zirconia–silica catalyst. By adding ammonium sulfate to the sol-gel synthesis system, the surface area, pore size, and pore volume of the resultant catalyst were increased. The one-pot sol-gel synthesized catalyst with an optimum loading of SO42– 14 mol% showed significantly higher catalytic activity, with a selectivity of 100%, for isopropanol dehydration when compared to the impregnated catalyst. The one-pot sol-gel synthesis method is an effective way to prepare sulfated zirconia catalyst.Key words: sulfated zirconia, sol-gel synthesis, acid catalyst, alcohol dehydration, N2 adsorption, DRIFT.

scholarly journals Chromium oxide zirconia solid acid catalyst for n-pentane isomerization

2014 ◽  
Vol 10 (4) ◽  
Author(s):  
Nur Hazirah Rozali Annuar ◽  
Aishah Abdul Jalil ◽  
Sugeng Triwahyono
Keyword(s):  
Physical Properties ◽  
Surface Area ◽  
Chromium Oxide ◽  
Solid Acid ◽  
Solid Acid Catalyst ◽  
Sol Gel ◽  
Acid Catalyst ◽  
Acid Sites ◽  
Bet Surface Area ◽  
Gel Technique

New catalyst based on zirconia (ZrO2) supported by chromium oxide (CrO3) for isomerization of n-pentane was studied. CrO3-ZrO2 was prepared with chromium nitrate by the titration and sol-gel technique. The physical properties of the catalysts were characterized by XRD, BET surface area analyzer, and TEM. The acidity and structure of catalysts were determined by pyridine and lutidine preadsorbed FTIR spectroscopy.  The isomerization of n-pentane was carried out at 523 K under hydrogen stream. CrO3-ZrO2 shows the differences in terms of physical properties where the introduction CrO3 partially eliminated the monoclinic phase of ZrO2 and developed new peaks assigned to tetragonal phase of ZrO2. CrO3-ZrO2 also shows a higher specific surface area where it increases in the pore volume of the catalyst compare to its parent zirconia.  The IR results indicated that CrO3-ZrO2 catalyst have strong Lewis and weak Brønsted acid sites. The conversion of n-pentane for CrO3-ZrO2 was 32% respectively, while the selectivity to iso-pentane was 100%. ________________________________________GRAPHICAL ABSTRACT

Studies on the Catalytic Activity of Sulfated Zirconia Promoted with Cerium Oxide

2010 ◽  
Vol 132 ◽  
pp. 149-161 ◽  
Author(s):  
F.E. Lugo del Ángel ◽  
R. Silva-Rodrigo ◽  
A. Vázquez Rodríguez ◽  
R. García Alamilla ◽  
J. Navarrete Bolaños ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Surface Area ◽  
Cerium Oxide ◽  
Sulfated Zirconia ◽  
Tetragonal Phase ◽  
Zirconium Oxide ◽  
Sol Gel ◽  
Reaction Products ◽  
Cerium Content ◽  
Methyl Pentane

Pure zirconia, sulfated zirconia and sulfated zirconia modified with 2, 3, 5 and 10 wt. % of cerium oxide were synthesized by sol-gel method. Pt phase was impregnated on the supports using the incipient wet technique. Sulfated zirconium oxide showed tetragonal phase only. Addition of cerium to sulfated zirconia did not modify the tetragonal phase but produced a marked effect on the surface area. Low cerium content may greatly increase the surface area; however, too high cerium content (10 wt.%) may decrease the surface area. Pore size had influence on the catalytic activity and ZrO2 acidity was favored by the sulfate ion incorporation. All catalysts having Brönsted and Lewis acid sites were active in the n-hexane isomerization. The highest n-hexane conversion (40%) and selectivity towards DMB (26%), 2-methyl pentane (61%) and 3-methyl pentane (13%) were reached over the catalyst with 10 wt. % cerium oxide. In addition, sulfated zirconium oxide presented high selectivity of light products (< C6), which indicated that the addition of this doping agent (CeO2) made the catalysts more selective toward the desired reaction products.

Hydrothermal Synthesis of Nanorods/Nanoparticles TiO2 for Photocatalytic Activity and Dye-sensitized Solar Cell Applications

2006 ◽  
Vol 951 ◽  
Author(s):  
Sorapong Pavasupree ◽  
Supachai Ngamsinlapasathian ◽  
Yoshikazu Suzuki ◽  
Susumu Yoshikawa
Keyword(s):  
Photocatalytic Activity ◽  
Surface Area ◽  
Pore Diameter ◽  
Mesoporous Structure ◽  
Energy Conversion Efficiency ◽  
Bet Surface Area ◽  
Average Pore ◽  
Dye Sensitized ◽  
Prepared Material ◽  
20 Nm

ABSTRACTNanorods/nanoparticles TiO2 with mesoporous structure were synthesized by hydrothermal method at 150 °C for 20 h. The samples characterized by XRD, SEM, TEM, SAED, HRTEM, and BET surface area. The nanorods had diameter about 10-20 nm and the lengths of 100-200 nm, the nanoparticles had diameter about 5-10 nm. The prepared material had average pore diameter about 7-12 nm. The BET surface area and pore volume of the sample are about 203 m2/g and 0.655 cm3/g, respectively. The nanorods/nanoparticles TiO2 with mesoporous structure showed higher photocatalytic activity (I3− concentration) than the nanorods TiO2, nanofibers TiO2, mesoporous TiO2, and commercial TiO2 (ST-01, P-25, JRC-01, and JRC-03). The solar energy conversion efficiency (η) of the cell using nanorods/nanoparticles TiO2 with mesoporous structure was about 7.12 % with Jsc of 13.97 mA/cm2, Voc of 0.73 V and ff of 0.70; while η of the cell using P-25 reached 5.82 % with Jsc of 12.74 mA/cm2, Voc of 0.704 V and ff of 0.649.

Synthesis and Characterizations of Titanium Tungstophosphate Nanoparticles for Heavy Metal Ions Removal

2016 ◽  
Vol 257 ◽  
pp. 187-192 ◽  
Author(s):  
Mohamed Ali Ghanem ◽  
Nezar H. Khdary ◽  
Abdullah M. Almayouf ◽  
Mabrook A. Salah
Keyword(s):  
Metal Ions ◽  
Surface Area ◽  
Self Assembly ◽  
Sol Gel ◽  
Bet Surface Area ◽  
Ionic Exchange ◽  
Characteristic Structure ◽  
X Ray ◽  
Heavy Metal Ions Removal ◽  
Metal Ions Removal

Ionic exchange of multi-components titanium tungstophosphate nanoparticles (TiWP-NPs) were prepared using sol-gel reaction of titanium isoperoxide and tungestophosphoric acid (TPA) in presence of CTAB surfactant. The X-ray, BET and TEM characterizations showed that the nanoparticles exhibit the characteristic structure of titanium tungstophosphate and a BET surface area of 74 ± 3 m2/g was achieved. The TPA has shown an effect on the self-assembly process and maintains the TPA content to minimum would be beneficial for obtaining higher surface area of TiWP nanoparticles. Metal ions adsorption of Cu(II), Pb(II) or Cd(II) using the resulting titanium tungstophosphate nanparticles materials is investigated and up to 95% removal percentage was achieved. Using this method, nanoparticles of ionic exchange titanium tungstophosphate can be synthesized in the form of powder and amenable to mass production.

Coupling Sol-Gel Synthesis and Microwave-Assisted Techniques: A New Route from Amorphous to Crystalline High-Surface-Area Aluminium Fluoride

2008 ◽  
Vol 14 (20) ◽  
pp. 6205-6212 ◽  
Author(s):  
Damien Dambournet ◽  
Gehan Eltanamy ◽  
Alexandre Vimont ◽  
Jean-Claude Lavalley ◽  
Jean-Michel Goupil ◽  
...  
Keyword(s):  
Surface Area ◽  
High Surface ◽  
Sol Gel ◽  
High Surface Area ◽  
Microwave Assisted ◽  
Aluminium Fluoride ◽  
Sol Gel Synthesis

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.

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

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