Influence of the molar ratio SiO2∶Al2O3 in super-high silica zeolite on the acidic and catalytic properties of palladium catalysts in isomerization of C8 aromatic hydrocarbons

1985 ◽  
Vol 27 (2) ◽  
pp. 343-346
Author(s):  
V. L. Baiburskii ◽  
T. A. Anokhina ◽  
S. N. Khadzhiev ◽  
I. L. Aleksandrova ◽  
V. A. Plakhotnik
Keyword(s):  
Aromatic Hydrocarbons ◽  
Palladium Catalysts ◽  
Catalytic Properties ◽  
Molar Ratio ◽  
High Silica

Polymetallic Catalysts for the Process of Hydrogenation of Nitrocompounds

2014 ◽  
Vol 618 ◽  
pp. 238-242
Author(s):  
Yermoldina Elmira ◽  
Kayrbekov Zhaksyntay ◽  
Aity Kali ◽  
Vasilina Gulzira
Keyword(s):  
Humic Substances ◽  
Palladium Catalysts ◽  
Catalytic Properties ◽  
Potassium Humate

Results of studies of humic substances in the quality of natural polymeric modifier for the coated palladium catalysts are presented in the paper, along with synthesis of new catalysts based on palladium – potassium humate, fixed on various inorganic carriers and their catalytic properties are studied. The catalysts may be placed in the following order according to activity: Pd-PHum/B-094 > Pd-PHum/Shungit (Sht), proc.1%КОН > Pd-PHum/Sht >> Pd-PHum/SiO2. More active and optimal are the catalysts of 0,8% Pd – Potassium’s Humat (1%)/B-94 and 0,8% Pd/Shungit 1% КОН.

Isomorphous rare-earth tris[bis(2,6-diisopropylphenyl) phosphate] complexes and their catalytic properties in 1,3-diene polymerization and in the inhibited oxidation of polydimethylsiloxane

2018 ◽  
Vol 74 (5) ◽  
pp. 590-598 ◽  
Author(s):  
Mikhail E. Minyaev ◽  
Alexander N. Tavtorkin ◽  
Sof'ya A. Korchagina ◽  
Galina N. Bondarenko ◽  
Andrei V. Churakov ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Catalytic Properties ◽  
Molar Ratio ◽  
High Catalytic Activity ◽  
Catalytic Systems ◽  
Neodymium Complex ◽  
Butadiene Polymerization ◽  
Bond Network ◽  
Phosphate Ligands ◽  
Monodentate Coordination

Crystals of mononuclear tris[bis(2,6-diisopropylphenyl) phosphato-κO]pentakis(methanol-κO)lanthanide methanol monosolvates of lanthanum, [La(C24H34O4P)3(CH3OH)5]·CH3OH, (1), cerium, [Ce(C24H34O4P)3(CH3OH)5]·CH3OH, (2), and neodymium, [Nd(C24H34O4P)3(CH3OH)5]·CH3OH, (3), have been obtained by reactions between LnCl3(H2O) n (n = 6 or 7) and lithium bis(2,6-diisopropylphenyl) phosphate in a 1:3 molar ratio in methanol media. Compounds (1)–(3) crystallize in the monoclinic P21/c space group and have isomorphous crystal structures. All three bis(2,6-diisopropylphenyl) phosphate ligands display a κO-monodentate coordination mode. The coordination number of the metal atom is 8. Each [Ln{O2P(O-2,6-iPr2C6H3)2}3(CH3OH)5] molecular unit exhibits four intramolecular O—H...O hydrogen bonds, forming six-membered rings. The unit forms two intermolecular O—H...O hydrogen bonds with one noncoordinating methanol molecule. All six hydroxy H atoms are involved in hydrogen bonding within the [Ln{O2P(O-2,6-iPr2C6H3)2}3(CH3OH)5]·CH3OH unit. This, along with the high steric hindrance induced by the three bulky diaryl phosphate ligands, prevents the formation of a hydrogen-bond network. Complexes (1)–(3) exhibit disorder of two of the isopropyl groups of the phosphate ligands. The cerium compound (2) demonstrates an essential catalytic inhibition in the thermal decomposition of polydimethylsiloxane in air at 573 K. Catalytic systems based on the neodymium complex tris[bis(2,6-diisopropylphenyl) phosphato-κO]neodymium, (3′), which was obtained as a dry powder of (3) upon removal of methanol, display a high catalytic activity in isoprene and butadiene polymerization.

Direct synthesis of high-silica nano ZSM-5 aggregates with controllable mesoporosity and enhanced catalytic properties

RSC Advances ◽  
2016 ◽  
Vol 6 (101) ◽  
pp. 99129-99138 ◽  
Author(s):  
Hongyao Li ◽  
Yaquan Wang ◽  
Fanjun Meng ◽  
Hengbao Chen ◽  
Chao Sun ◽  
...  
Keyword(s):  
Catalytic Properties ◽  
Direct Synthesis ◽  
High Silica

In the absence of additional mesoporous template, high-silica nano-sized ZSM-5 aggregates have been rapidly synthesized by solid-like state conversion.

Catalytic properties of high-silica zeolites in hydrotreatment of coal liquefaction products

Fuel ◽  
1997 ◽  
Vol 76 (7) ◽  
pp. 683-685 ◽  
Author(s):  
Andrey A. Krichko ◽  
Anatoly S. Maloletnev ◽  
Olga A. Mazneva ◽  
Sergey G. Gagarin
Keyword(s):  
Catalytic Properties ◽  
Coal Liquefaction ◽  
High Silica ◽  
High Silica Zeolites ◽  
Coal Liquefaction Products

Influence of thermal and hydrothermal activation on the adsorptive, acidic and catalytic properties of high-silica zeolites

1984 ◽  
Vol 24 (3-4) ◽  
pp. 277-280 ◽  
Author(s):  
Yu. V. Shumovskii ◽  
S. N. Khadzhiev ◽  
M. I. Levinbuk ◽  
T. V. Limova
Keyword(s):  
Catalytic Properties ◽  
High Silica ◽  
High Silica Zeolites

scholarly journals Hierarchical Low Si/Al Ratio Ferrierite Zeolite by Sequential Postsynthesis Treatment: Catalytic Assessment in Dehydration Reaction of Methanol

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Enrico Catizzone ◽  
Massimo Migliori ◽  
Alfredo Aloise ◽  
Rossella Lamberti ◽  
Girolamo Giordano
Keyword(s):  
Textural Properties ◽  
Vapour Phase ◽  
Solution Concentration ◽  
Methanol Conversion ◽  
Molar Ratio ◽  
Light Hydrocarbons ◽  
Hierarchical Zeolites ◽  
Type Zeolite ◽  
High Silica ◽  
High Silica Zeolites

In contrast to high silica zeolites, it is difficult to obtain mesoporosity in zeolites with low Si/Al ratio (e.g., <20) via conventional NaOH-based treatment, making the obtainment of hierarchical zeolites with high acidity a challenging target. In this paper, we report the preparation of hierarchical FER-type zeolite at low Si/Al molar ratio (about 10) by postsynthesis etching involving a sequence of three treatments with NaAlO2, HCl, and NaOH solutions and investigate the effect of both NaAlO2 solution concentration and time of treatment on the textural properties. The obtained materials exhibit a mesoporous volume higher than the parent ferrierite with no significant effect on the sample acidity. The catalytic activity of some samples was investigated in vapour-phase methanol dehydration to dimethyl ether, revealing the superiority of hierarchical zeolites in terms of methanol conversion, although the presence of mesopores causes formation of light hydrocarbons at high temperatures.

scholarly journals Heterogeneous Fenton-like oxidation of p-hydroxybenzoic acid using Fe/CeO2-TiO2 catalyst

2019 ◽  
Vol 79 (7) ◽  
pp. 1276-1286 ◽  
Author(s):  
Tijani Hammedi ◽  
Mohamed Triki ◽  
Mayra G. Alvarez ◽  
Jordi Llorca ◽  
Abdelhamid Ghorbel ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Catalytic Properties ◽  
Molar Ratio ◽  
Hydroxybenzoic Acid ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Temperature Programmed

Abstract This paper is built on the Fenton-like oxidation of p-hydroxybenzoic acid (p–HBZ) in the presence of H2O2 and 3%Fe supported on CeO2-TiO2 aerogels under mild conditions. These catalysts were deeply characterized by X-ray diffraction (XRD), hydrogen temperature programmed reduction (H2-TPR), transmission electron microscopy (TEM), scanning transmission electron microscopy (STEM) and X-ray photoelectron spectroscopy (XPS). The effect of thermal treatment, pH (2–3, 5, 7), H2O2/p–HBZ molar ratio (5, 15, 20, 25) and reaction temperature (25 °C, 40 °C and 60 °C) on the catalytic properties of supported Fe catalysts are studied. Our results highlight the role of CeO2 and the calcination of the catalyst to obtain the highest catalytic properties after 10 min: 73% of p–HBZ conversion and 52% of total organic carbon (TOC) abatement.

The Influence of the Dealumination of the High Silica Zeolite ZVM on the Character of OH groups and the Catalytic Properties

1989 ◽  
Vol 270 (1) ◽  
pp. 1-4 ◽  
Author(s):  
K.-H. Schnabel ◽  
U. Lohse ◽  
Ch. Peuker ◽  
D. Freude ◽  
O. V. Bragin ◽  
...  
Keyword(s):  
Catalytic Properties ◽  
Oh Groups ◽  
High Silica
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