Sol-gel synthesis of ternary phosphate-ZrO2-SiO2 catalysts for alcohol dehydration

2001 ◽  
Vol 79 (8) ◽  
pp. 1224-1228 ◽  
Author(s):  
Quan Zhuang ◽  
Jack M Miller
Keyword(s):  
Key Words ◽  
Sol Gel ◽  
Acid Catalyst ◽  
Tetraethyl Orthosilicate ◽  
Mas Nmr ◽  
Alcohol Dehydration ◽  
Zirconium Propoxide ◽  
P Content ◽  
Sol Gel Synthesis ◽  
Cp Mas Nmr

Phosphate–ZrO2–Si2O catalysts were synthesized by sol-gel method using tributyl phosphite, zirconium propoxide, and tetraethyl orthosilicate as precursors. They were characterized by N2 adsorption, 31P CP MAS NMR, and DRIFTS. At lower P content, monomeric phosphates were formed on the surface of the catalysts, which were mainly responsible for the isopropanol dehydration activity. At higher P content, polyphosphates were formed, and thus, the dehydration activity decreased. An optimum P content for dehydration activity was found to be at 10 mol%.Key words: sol-gel synthesis, ternary oxides, phosphate, acid catalyst, alcohol dehydration, 31P CP MAS NMR, N2 adsorption, DRIFTS.

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.

Synthesis of Hybrid Organic-Inorganic Sol-Gel Coatings for Corrosion Resistance

1999 ◽  
Vol 576 ◽  
Author(s):  
T. L. Metroke ◽  
R. L. Parkhill ◽  
E. T. Knobbe
Keyword(s):  
Corrosion Resistance ◽  
Salt Spray ◽  
Sol Gel ◽  
Organic Content ◽  
Film Structure ◽  
Mas Nmr ◽  
Silica Network ◽  
Nmr Data ◽  
Acid Catalyzed ◽  
Cp Mas Nmr

ABSTRACT1H-13C and 1H- 29Si CP/MAS NMR spectroscopy has been used to characterize the structure of sol-gel derived hybrid materials prepared from 3-glycidoxypropyltrimethoxysilane (GLYMO) and tetraethylorthosilicate (TEOS) as a function of hydrolysis water ratio and organic content. 1H-13C CP/MAS NMR data indicate that the concentration of hydrolysis water (R value) has a fundamental effect on the nature of the acid-catalyzed hydrolysis and ring opening products. 1H-29Si CP/MAS NMR data suggest that for low R values, the ormosils are composed of a silica network with epoxide groups randomly dispersed throughout. At high R values, epoxide functionalities were found to coat the surfaces of dense silica particles. Salt spray analysis indicates that the corrosion resistance behavior of thin films derived from GLYMOTEOS ormosils decreases as the concentration of hydrolysis water increases and improves as the organic content in the film increases. These observations can be related to the underlying thin film structure.

Nanoscopic yttrium oxide fluorides: non-aqueous fluorolytic sol–gel synthesis and structural insights by 19F and 89Y MAS NMR

2015 ◽  
Vol 44 (30) ◽  
pp. 13522-13529 ◽  
Author(s):  
G. Scholz ◽  
M. Dreger ◽  
R. Bertram ◽  
E. Kemnitz
Keyword(s):  
Yttrium Oxide ◽  
Sol Gel ◽  
Mas Nmr ◽  
Yttrium Acetate ◽  
Oxide Fluorides ◽  
Sol Gel Synthesis ◽  
Structural Insights

Nanoscopic yttrium acetate fluorides Y(CH3COO)3−zFz and yttrium oxide fluorides YO(3−z)/2Fz were prepared via the fluorolytic sol–gel route and studied by 19F and 89Y MAS NMR.

Room temperature sol–gel synthesis of crystalline Cs[V3O8]. Probing the hydration level of the interlamellar space by 51V and 133Cs MAS NMR spectroscopy

2008 ◽  
Vol 18 (31) ◽  
pp. 3702 ◽  
Author(s):  
Olivier Durupthy ◽  
Jocelyne Maquet ◽  
Christian Bonhomme ◽  
Thibaud Coradin ◽  
Jacques Livage ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Room Temperature ◽  
Sol Gel ◽  
Mas Nmr ◽  
Hydration Level ◽  
Interlamellar Space ◽  
Sol Gel Synthesis

Sol–gel synthesis of Ta2O5–SiO2 composites from tantalum(V) chloride and tetraethyl orthosilicate in ethanol

2017 ◽  
Vol 53 (9) ◽  
pp. 994-1003 ◽  
Author(s):  
A. G. Mal’chik ◽  
S. A. Kuznetsova ◽  
S. O. Kryuchkova ◽  
V. V. Kozik
Keyword(s):  
Sol Gel ◽  
Tetraethyl Orthosilicate ◽  
Sol Gel Synthesis

Preparation of a Silicon Oximide Gel via a Non-Aqueous Sol-Gel Route

2002 ◽  
Vol 726 ◽  
Author(s):  
Fei Cheng ◽  
John S. Bradley
Keyword(s):  
Amorphous Silicon ◽  
Surface Area ◽  
Sol Gel ◽  
Total Surface Area ◽  
Mas Nmr ◽  
Bet Surface Area ◽  
Molar Ratio ◽  
Microporous Structure ◽  
Silicon Oxycarbonitride ◽  
Cp Mas Nmr

AbstractA silicon oximide gel was prepared by a reaction in N,N-dimethylformamide between tris(dimethylamino)silylamine (Me2N)3SiNH2 (TDSA) and formamide in a 1:2 molar ratio at 50C. The 29Si, 13C CP-MAS NMR and IR analyses indicated that the gel mainly comprised oximino silicon networks [SiOC(H)=NSi]x. The gel exhibited a microporous structure and had a total surface area of 339 m2/g. A microporous structure with a BET surface area of 195 m2/g was also obtained after pyrolysis of the gel at 1000°C for 2 h. Pyrolysis of the gel under N2 up to 1485°C gave an amorphous silicon oxycarbonitride glass.

Copolymers and Proton Conducting Films Based on N-Vinylpyrazole

2013 ◽  
Vol 749 ◽  
pp. 71-76 ◽  
Author(s):  
Oksana Lebedeva ◽  
Yury Pozhidaev ◽  
Evgenya Sipkina ◽  
Alexandra Chesnokova ◽  
Nikolay Ivanov
Keyword(s):  
Methyl Methacrylate ◽  
Radical Polymerization ◽  
Proton Conductivity ◽  
Vinyl Chloride ◽  
Sol Gel ◽  
Tetraethyl Orthosilicate ◽  
Proton Conducting ◽  
Inorganic Composites ◽  
Microstructure Parameters ◽  
Sol Gel Synthesis

The copolymers of N-vinylpyrazole with vinyl chloride and methyl methacrylate were obtained by radical polymerization. Constants reactivity and microstructure parameters of copolymers were calculated and their properties were studied. The sol-gel synthesis of obtained copolymers with tetraethyl orthosilicate results in a hybrid organic-inorganic composites. Films with proton conductivity to 7.8·10-3 S·sm-1 were formed on the basis the copolymers and composites.

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 Thermal degradation of aluminum formate sol-gel; synthesis of α-alumina and characterization by 1 H, 13 C and 27 Al MAS NMR and XRD spectroscopy

2016 ◽  
Vol 6 ◽  
pp. 1096-1102 ◽  
Author(s):  
José H. Roque-Ruiz ◽  
Erick A. Cabrera-Ontiveros ◽  
Gerardo González-García ◽  
Simón Y. Reyes-López
Keyword(s):  
Thermal Degradation ◽  
Sol Gel ◽  
Mas Nmr ◽  
Sol Gel Synthesis
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