Sulfur-Coordinated Thiophene and Benzothiophene in Cp(NO)(PPh3)Re(thiophene)+: Conversion to Thienyl and Thienylcarbene Complexes

1994 ◽  
Vol 116 (12) ◽  
pp. 5190-5195 ◽  
Author(s):  
Mitchell J. Robertson ◽  
Carter J. White ◽  
Robert J. Angelici
Keyword(s):  
Thiophene Conversion

scholarly journals Adsorption Parameters and Surface Species in the Nickel—Molybdenum Alumina System

1989 ◽  
Vol 6 (4) ◽  
pp. 192-211 ◽  
Author(s):  
R.A.E. Rodriguez ◽  
G.J. Siri ◽  
C.V. Cáceres ◽  
H.J. Thomas
Keyword(s):  
Nickel Content ◽  
Catalyst System ◽  
Atomic Ratio ◽  
Convincing Evidence ◽  
Intrinsic Activity ◽  
Adsorption Parameters ◽  
Low Concentrations ◽  
Thiophene Conversion ◽  
High Concentrations ◽  
Molybdenum Concentration

Isotherms corresponding to the adsorption of ammonium heptamolybdate solutions on nickel–alumina supports have been studied. Such isotherms exhibit two distinct adsorption regions, with both the support and the adsorbed species contributing to their formation. Two types of site are available for adsorption on the support and, depending on the molybdenum concentration present in solution, either monomeric (at low concentrations) or polymeric molybdenum species (at high concentrations) are formed and adsorbed. Monomer adsorption occurs at low concentrations, whereas polyanion adsorption predominates at high concentrations; the latter is reflected in an abrupt increase in molybdenum concentration adsorbed on the support. The adsorption isotherms measured at 20°C and 50°C, and TPR and XPS studies indicate that the samples prepared at 50°C contain a lower quantity of octahedral molybdenum, although dispersion of the molybdenum on the surface is higher. In addition, a direct relationship exists between the dispersion of the active component and the hydrodesulphurization activity of the sample. The presence of nickel on the support does not affect the total number of sites occupied by molybdenum. However, when the nickel content on the solid is increased, the molybdenum species occupy a higher proportion of octahedral sites. XPS studies have shown that samples with a higher nickel content possess a better dispersion of molybdenum species and exhibit a higher intrinsic activity. Enhanced molybdenum dispersion and thiophene conversion was associated with samples in which molybdenum adsorption occurred before nickel impregnation. For all the series studies, the maximum value in the intrinsic acitivity occurred at the same value of the Ni/Mo atomic ratio. This provides convincing evidence that the precursor ratio is important in this catalyst system.

scholarly journals Improvement of HDS catalysts through the modification of the oxidic precursor with 1,5-pentanediol: Gas phase sulfidation and thiophene conversion

2016 ◽  
Vol 19 (10) ◽  
pp. 1286-1302 ◽  
Author(s):  
Pascal Blanchard ◽  
Naïma Frizi ◽  
Soazic Mary ◽  
Pascale Baranek ◽  
Christine Lancelot ◽  
...  
Keyword(s):  
Gas Phase ◽  
Hds Catalysts ◽  
Thiophene Conversion

Effect of Heteroatom on Properties of SiO2-Supported Heteropolymolybdates

1998 ◽  
Vol 63 (11) ◽  
pp. 1927-1937 ◽  
Author(s):  
Alla Spojakina ◽  
Nina Kostova ◽  
Květa Jirátová
Keyword(s):  
Ir Spectroscopy ◽  
Lithium Salts ◽  
Temperature Programmed Reduction ◽  
Thiophene Conversion ◽  
Keggin Anions ◽  
Temperature Programmed

SiO2-supported trihydrogen phosphododecamolybdate acid H3PMo12O40 (denoted as H3PMo) and tetrahydrogen silicododecamolybdate acid H4SiMo12O40 (denoted as H4SiMo) and their lithium salts have been studied using IR spectroscopy, temperature programmed reduction and measurement of the thiophene conversion. Lacunar anions of H3PMo and, under some conditions, of H4SiMo are formed if lithium is present in the catalyst. Unlike the supported hetero polyacids, lithium combined with the analogues of defect Keggin anions formed during calcination enhances hydrodesulfurization of thiophene.

Characterization and reactivity of sulfided NiNaY zeolite catalysts for thiophene conversion

Zeolites ◽  
1990 ◽  
Vol 10 (2) ◽  
pp. 95-100 ◽  
Author(s):  
R. Cid ◽  
J.L.G. Fierro ◽  
A. López Agudo
Keyword(s):  
Zeolite Catalysts ◽  
Thiophene Conversion

Surface Properties and Catalytic Behaviour in Thiophene Hydrodesulfurization on Mo- and NiMo-Modified HZSM-5 Zeolites

1992 ◽  
Vol 57 (12) ◽  
pp. 2509-2514 ◽  
Author(s):  
Alla A. Spojakina ◽  
Nina G. Kostova
Keyword(s):  
Ir Spectroscopy ◽  
Ir Spectra ◽  
Surface Properties ◽  
Strong Interaction ◽  
Shape Selectivity ◽  
Reduction Treatment ◽  
Zeolite Lattice ◽  
Thiophene Hydrodesulfurization ◽  
Thiophene Conversion ◽  
Catalytic Behaviour

Zeolite HZSM-5 containing 1 wt.% Ni and 10 wt.% Mo has been investigated using IR spectroscopy and thiophene hydrodesulfurization (HDS). The IR spectra indicate the strong interaction of molybdenum and nickel with zeolite lattice, forming polymolybdates of different composition. The acidity of the samples is influenced by the composition and reduction treatment. The zeolite is found to exhibit shape selectivity during thiophene conversion.

Hydrodesulphurization of Thiophene over Co, Mo and CoMo /g-Al2O3 Catalysts

2018 ◽  
Vol 69 (2) ◽  
pp. 396-399
Author(s):  
Rami Doukeh ◽  
Ancuta Trifoi ◽  
Mihaela Bombos ◽  
Ionut Banu ◽  
Minodora Pasare ◽  
...  
Keyword(s):  
Fixed Bed ◽  
Molar Ratio ◽  
Catalytic Reactor ◽  
Monometallic Catalysts ◽  
Thiophene Conversion ◽  
C 30 ◽  
Al2o3 Catalyst

The hydrodesulphurization (HDS) of thiophene was performed on monometallic catalysts Co/g -Al2O3, Mo/g -Al2O3 and bimetallic CoMo/g -Al2O3. Experiments were carried out on a fixed bed catalytic reactor at 175-300�C, 30-60 atm, thiophene volume hourly space velocities of 1h-1- 4h-1 and molar ratio hydrogen/thiophene of 60/1. The thiophene conversion on the bimetallic CoMo/g -Al2O3 catalyst was higher than on Co/g -Al2O3 or Mo/g -Al2O3.

Thiophene conversion under mild conditions over a ZSM-5 catalyst

2009 ◽  
Vol 64 (11) ◽  
pp. 2539-2561 ◽  
Author(s):  
Lisette Jaimes ◽  
M. Lujan Ferreira ◽  
Hugo de Lasa
Keyword(s):  
Mild Conditions ◽  
Thiophene Conversion

Thiophene conversion in the BIMF process

2004 ◽  
Vol 83 (1) ◽  
pp. 187-194 ◽  
Author(s):  
D.G. Aksenov ◽  
O.V. Klimov ◽  
G.V. Echevskii ◽  
E.A. Paukshtis ◽  
A.A Budneva
Keyword(s):  
Thiophene Conversion

Characterization of Mo-Containing Systems Supported on AlPO4-5 and Aluminium Phosphate and Their Behavior in Thiophene Conversion

1992 ◽  
Vol 57 (4) ◽  
pp. 836-844 ◽  
Author(s):  
Alla A. Spojakina ◽  
Nina G. Kostova ◽  
Ljubomir Dimitrov
Keyword(s):  
Hydrogen Sulfide ◽  
Ir Spectroscopy ◽  
Chemical Interaction ◽  
Aluminium Phosphate ◽  
Thiophene Conversion ◽  
The Difference ◽  
The Impact

The properties of AlPO4-5 with zeolite-like structure and amorphous aluminium phosphate modified by nickel and/or molybdenum (1 wt.% and 10 wt.%, respectively) have been studied using ESR and IR spectroscopy and catalytic testing in hydrodesulfurization (HDS) of thiophene. The chemical interaction between all components of catalysts with formation of polymolybdate structures is revealed. The impact of the support is reflected in the difference of composition of polymolybdates, and different interactions with the hydrogen sulfide eliminated in thiophene conversion. The selectivity of the thiophene conversion and adsorption of H2S eliminated depend on the method of introduction of components only for AlPO4-5.

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