Participation of molecular hydrogen-originated protonic acid sites in acid-catalyzed reactions

1998 ◽  
Vol 24 (4) ◽  
pp. 439-448 ◽  
Author(s):  
Hideshi Hattori ◽  
Takayuki Yamada ◽  
Tetsuya Shishido
Keyword(s):  
Molecular Hydrogen ◽  
Acid Sites ◽  
Protonic Acid ◽  
Acid Catalyzed ◽  
Catalyzed Reactions

Catalytic Properties of Fluorine Modified SmNa-Y Zeolites

1992 ◽  
Vol 57 (4) ◽  
pp. 781-787 ◽  
Author(s):  
Stanisłav Kowalak ◽  
Maria Pawłowska ◽  
Kenneth J. Balkus
Keyword(s):  
Catalytic Properties ◽  
Acid Sites ◽  
Y Zeolites ◽  
Cumene Cracking ◽  
Toluene Disproportionation ◽  
Zeolite Nay ◽  
Polyvalent Cations ◽  
Protonic Acid ◽  
Acid Catalyzed ◽  
Catalyzed Reactions

It is known that mild fluorination of zeolites, including those modified with polyvalent cations, increases their activity for acid catalyzed reactions. In this study we report the reactivity of fluorine modified Sm(III) exchanged zeolite NaY. Mild fluorination of SmNaY reduces the activity of strong protonic acid sites and increases the contribution of weak aprotic acid centres. Results for cumene cracking and toluene disproportionation as well as for 1-hexene isomerization are reported.

scholarly journals Enhancement of HDO Activity of MoP/SiO2 Catalyst in Physical Mixture with Alumina or Zeolites

Catalysts ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 45 ◽  
Author(s):  
Ivan V. Shamanaev ◽  
Irina V. Deliy ◽  
Evgeny Yu. Gerasimov ◽  
Vera P. Pakharukova ◽  
Galina A. Bukhtiyarova
Keyword(s):  
Catalytic Properties ◽  
Acid Sites ◽  
Physical Mixture ◽  
Reaction Route ◽  
Zeolite Β ◽  
Acid Catalyzed ◽  
Catalyzed Reactions ◽  
Metal Catalyzed ◽  
High Level ◽  
Xrd And Tem

Catalytic properties of physical mixture of MoP/SiO2 catalyst with SiC, γ-Al2O3, SAPO-11 and zeolite β have been compared in hydrodeoxygenation of methyl palmitate (MP). MoP/SiO2 catalyst (11.5 wt% of Mo, Mo/P = 1) was synthesized using TPR method and characterized with N2 physisorption, elemental analysis, H2-TPR, XRD and TEM. Trickle-bed reactor was used for catalytic properties investigation at hydrogen pressure of 3 MPa, and 290 °C. The conversions of MP and overall oxygen-containing compounds have been increased significantly (from 59 to about 100%) when γ-Al2O3 or zeolite materials were used instead of inert SiC. MP can be converted to palmitic acid through acid-catalyzed hydrolysis along with metal-catalyzed hydrogenolysis, and as a consequence the addition of material possessing acid sites to MoP/SiO2 catalyst could lead to acceleration of MP hydrodeoxygenation through acid-catalyzed reactions. Isomerization and cracking of alkane were observed over the physical mixture of MoP/SiO2 with zeolites, but the selectivity of MP conversion trough the HDO reaction route is remained on the high level exceeding 90%.

Enhancemen Effect of Hydrogen Sulfide Over Metal Ion-Exchange Mesoporous Silicate FSM-16 for Acid Catalyzed Reactions.

2005 ◽  
Vol 5 (1) ◽  
pp. 76
Author(s):  
Lebong Andalaluna ◽  
Masatoshi Sugioka
Keyword(s):  
Hydrogen Sulfide ◽  
Ion Exchange ◽  
Metal Ion ◽  
Acid Sites ◽  
Enhancement Effect ◽  
Mesoporous Silicate ◽  
Acid Catalyzed ◽  
Activity Enhancement ◽  
Catalyzed Reactions ◽  
Metal Ion Exchange

The activity enhancement of metal ion-exchange mesoporous silicate FSM-16 (MeFSM-16) by sulfiding with hydrogen sulfide was studied using acid-catalyzed reactions, isomerization of I-butene, cis-2-butene and cyclopropane, as model reactions. It was revealed that the catalytic activities of MeFSM-16 for the acid-catalyzed reactions were remarkably enhanced after sulfiding with hydrogen sulfide. Moreover, it was observed that the optimum enhancement effect of hydrogen sulfide was obtained at the sulfiding temperature of 200°C. Infrared spectroscopic measurement of pyridine adsorption over sulfided MeFSM-16 showed that the activity enhancement of MeFSM-16 resulted in the generation of new Bronsted acid sites. Keywords: Metal ion-exchange, mesoporous silicate, hydrogen sulfide, and activity enhancement.

Generation of protonic acid sites originating from molecular hydrogen over H-ZSM-5

1992 ◽  
Vol 48 (1) ◽  
pp. 17-22 ◽  
Author(s):  
Junpei Tsuji ◽  
Kohki Ebitani ◽  
Hideshi Hattori ◽  
Hideaki Kita
Keyword(s):  
Molecular Hydrogen ◽  
Acid Sites ◽  
Protonic Acid

scholarly journals Influence of Remaining Acid Sites of an Amorphous Aluminosilicate on the Oligomerization of n-Butenes after Impregnation with Nickel Ions

Catalysts ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1487
Author(s):  
Fabian Nadolny ◽  
Felix Alscher ◽  
Stephan Peitz ◽  
Ekaterina Borovinskaya ◽  
Robert Franke ◽  
...  
Keyword(s):  
Heterogeneous Catalysts ◽  
Acid Sites ◽  
Mesoporous Catalyst ◽  
Nickel Ions ◽  
Methyl Group ◽  
Before And After ◽  
Amorphous Aluminosilicate ◽  
Acid Catalyzed ◽  
Catalyzed Reactions ◽  
Group Migration

Highly linear octene isomers can be produced from n-butene on industrial scale by using Ni-containing aluminosilicates as heterogeneous catalysts. These catalysts can be prepared by impregnating an aluminosilicate with a Ni(II) salt solution. This leads to a competition between acid-catalyzed and nickel-catalyzed reactions. In this study it is shown that some octene isomers are exclusively formed via an acid-catalyzed mechanism as a result of methyl group migration at the surface of a mesoporous catalyst. Specifically, the isomers 4,4-dimethylhexene (4,4-DMH) and 3-ethyl-2-methylpentene (3E-2MP) exhibit a systematic correlation compared to the amount of 3,4-dimethylhexene (3,4-DMH) formed at acid sites. By analyzing the ratio of 4,4-DMH and/or 3E-2MP to 3,4-DMH in the product spectrum before and after impregnation with a nickel precursor, the extend of acid site covered by nickel ions can be evaluated.

Photoinduced rearrangement of hydroxymethylisoxazolines, a route to enaminoaldehydes

1986 ◽  
Vol 51 (10) ◽  
pp. 2167-2180 ◽  
Author(s):  
Lubor Fišera ◽  
Nadezhda D. Kozhina ◽  
Peter Oravec ◽  
Hans-Joachim Timpe ◽  
Ladislav Štibrányi ◽  
...  
Keyword(s):  
Thionyl Chloride ◽  
Quantum Yields ◽  
Acid Catalyzed ◽  
Catalyzed Reactions ◽  
Photoinduced Rearrangement ◽  
Condensed Heterocycles

3-Aryl-4-R-carbamoyl-5-hydroxymethylisoxazolines (IV) were synthesized by allowing R-NH2 amines with R = H, CH3, C3H7, C6H5C2H5, and NH2 to act on 3-(X-phenyl)-4-oxo-3a,4,6,6a-tetrahydrofuro[3,4-d]isoxazoles (III) with X = H, 4-CH3, 4-OCH3, 2-OCH3, 4-Cl, 2-Cl, 4-F, 2-F, 4-Br, 4-NO2, and 3-NO2. Exposed to radiation, the substances IV give Z-2-hydroxymethylamino-2-aryl-1-formylacrylamides (V) in good yields. The 4-Cl and 4-F substituted Z-derivatives V isomerize irreversibly to the E-derivatives VI if allowed to stand in solvent; the remaining derivatives V are stable. The quantum yields of the photoreaction are from 0.012 to 0.106 in dependence on the substituent X. In all cases where the compounds IV were used for the preparation of condensed heterocycles in conditions of acid-catalyzed reactions, lactones III were preferentially formed; the action of thionyl chloride on IV results in the formation of chloromethyl derivatives VIII, which do not undergo further cyclization.

Synthetic Scope of Brønsted Acid-Catalyzed Reactions of Carbonyl Compounds and Ethyl Diazoacetate

2021 ◽  
Author(s):  
Mizzanoor Rahaman ◽  
M. Shahnawaz Ali ◽  
Khorshada Jahan ◽  
Damon Hinz ◽  
Jawad Bin Belayet ◽  
...  
Keyword(s):  
Carbonyl Compounds ◽  
Bronsted Acid ◽  
Brønsted Acid ◽  
Ethyl Diazoacetate ◽  
Brönsted Acid ◽  
Acid Catalyzed ◽  
Catalyzed Reactions
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