نتایج جستجو برای: vanadium catalyst

تعداد نتایج: 51205  

The vanadium-based catalyst, acts as a homogeneous catalyst for the selective oxidation of various kinds of sulfides with 30% aqueous H2O2. Vanadium-based catalyst was successfully used as the oxygen source for the oxidation of sulfides to sulfoxides for the first time. The sulfoxides were obtained in a good way to high yields without any detectable over-oxidation to sulfones under normal condi...

Journal: :Chemical communications 2010
Shoichiro Sueoka Takato Mitsudome Tomoo Mizugaki Koichiro Jitsukawa Kiyotomi Kaneda

Monomeric vanadium oxide species is created on the surface of hydrotalcite (V/HT), which acts as a reusable solid catalyst for the highly efficient dehydration of amides into the corresponding nitriles.

A mild and efficient synthesis of polysubstituted dihydro-2-oxypyrroles has been developed for the one-pot, four-component domino condensation of dialkyl acetylenedicarboxylate, formaldehyde and aromatic amines using Vanadium (V) oxide as the catalyst at ambient temperature. The use of Vanadium (V) oxide makes this process simple, more convenient, and environmentally friendly.

Journal: Polyolefins Journal 2016

A novel imido-modified SiO2-supported Ti/Mg Ziegler-Natta catalyst for ethylene and ethylene/1-hexene polymerization is investigated. The catalyst is prepared by modification of (SiO2/MgO/MgCl2)TiClx Ziegler-Natta catalysts via supporting vanadium species followed by reaction with p-tolyl isocyanate as imido agents, to get the merits from both the SiO2-supported imido vanadium catalyst and the ...

2013
Michael North James M Watson

Structurally well-defined bimetallic titanium(IV) (salen) and monometallic vanadium(V) (salen) complexes have been used as catalysts for the asymmetric addition of trimethylsilyl cyanide to β-nitroalkenes to produce chiral nitronitriles with ee values in the range of 79-89 % and conversions up to 100 % at 0 °C. The reaction conditions (solvent, temperature, time and vanadium complex counter-ion...

Fateme Asjodi Seyyed Khatiboleslam Sadr Nejad

Vanadium is distributed widely and scarcely (150 ppm) on the earth. Its major applications are in steelmaking, dye-production and catalyst-fabrication industries. With the ever-increasing demand for this metal, secondary resource-exploitation of such waste materials as spent catalysts is recommended. Many reactions are involved in vanadium-extraction from these resources. Since roasting in comp...

Journal: :Industrial health 2002
Kazuhiro Sato Yukinori Kusaka Hironobu Akino Hiroshi Kanamaru Kenichiro Okada

Vanadium pentoxide is used as a catalyst and a ferrovanadium alloy ingredient in automotive steels and in jet engines and airframes. In addition, vanadium is found in fuel oils. Thus, occupational exposures to vanadium pentoxide and trioxide may occur during the cleaning of oil-fired ship boilers, and from oil-fired power station boilers. Occupational exposure to vanadium pentoxide induces gree...

Journal: Polyolefins Journal 2017

Chromium-vanadium (Cr-V) bimetallic catalysts are prepared by the introduction of vanadium into the Phillips catalyst which is one of the most significant industrial ethylene polymerization catalysts for tuning the Phillips catalyst performances and improving polyethylene properties. In the present work, titanium species were introduced into the fluorine-modified chromium-vanadium bimetallic ca...

2016
Dong Liu Xiangxin Xue Hugo F. Lopez

Vanadium is an important metal used almost exclusively in ferrous and non-ferrous alloys due to its physicochemical and mechanical properties such as grain refinement, high tensile strength, hardness and fatigue resistance; it has a wide range of uses in the metallurgical and chemical sectors [1–3]. There are mainly three kinds of raw materials, bone coal, vanadium slag and waste vanadium catal...

Journal: :Nippon kagaku zassi 1950

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