Cobalt oxide-molybdenum

An unanticipated catalytic reaction of olefinic hydrocarbons was described in 1964 by Banks and Bailey.1 2 They discovered that C3-C8 alkenes disproportionate to homologs of higher and lower molecular weight in the presence of alumina-supported molybdenum oxide [Eq. (12.1)], cobalt oxide-molybdenum oxide, molybdenum hexacarbonyl, or tungsten hexacarbonyl at 100-200°C, under about 30 atm pressure ... 

Disulfides can also be produced by passing mixtures of the mercaptan and air (or dilute oxygen in an inert gas) over copper or cobalt oxide/molybdenum oxide catalysts at elevated temperatures. 

Hydrotreating Generally, the first process before cracking. Petroleum fractions are reacted with hydrogen at 400°C with a cobalt oxide/molybdenum oxide catalyst [1], This decreases the amount of nitrogen and sulfur compounds and prevents poisoning. 

Then in 1970 Esso research and engineering filed [3] a series of patents over several years on the cobalt oxide/molybdenum oxide/caesium acetate supported alumina catalyst. This catalyst henceforth is called the Aldridge catalyst in tribute to its principal discoverer Clyde L. Aldridge at Esso. Acmally these patents describe a family of catalysts. Aldridge believes that the catalyst should have the following components to be active at as low as temperatures below 140 °C. 

A lower pressure could be used as far as the process is concerned but the high pressure allows use of one compressor for all three stages. The third stage reactor has only one catalyst bed and quench is not required. Aromatics hydrogenation also is minimal in this stage. The catalyst for the third stage is a cobalt oxide-molybdenum oxide/alumina formulation. 

H-Coal A coal gasification process. Crushed coal is mixed with process-derived oil and catalytically hydrogenated in an ebullated bed under pressure at 455°C. The catalyst is a mixture of cobalt and molybdenum oxides on alumina. Developed by Hydrocarbon Research from the 1960s and piloted in Catlettsburg, KY, from 1980 to 1982. See also CSF, H-Oil, CSF, Synthoil. 

IR spectra, 27 283, 284 magnetic measurements, 27 280 oxidized state, 27 289 Raman spectra, 27 284 reduced state, 27 291 reflectance spectroscopy, 27 279 X-ray diffraction, 27 272, 273 support interactions, 27 290 Cobalt monoxide, field effect, 27 44, 45 Cobalt(nickel)-molybdenum-sulfide catalysts, 42 417... 

Inorganic oxides exhibiting electrochromism include cobalt oxide, nickel oxide, molybdenum trioxide, vanadium oxide, tungsten trioxide and their mixtures. The most important of these are those based on tungsten trioxide. 

Reforming Both thermal and catalytic processes are utilized to convert naphtha fractions into high-octane aromatic compounds. Thermal reforming is utilized to convert heavy naphthas into gasoline-quality aromatics. Catalytic reforming is utilized to convert straight-run naphtha fractions into aromatics. Catalysts utilized include oxides of aluminum, chromium, cobalt, and molybdenum as well as platinum-based catalysts. 

Sumimoto introduced a new sebacic acid process including several catalytic hydrogenation reactions.342 The synthesis starts with naphthalene, which is first partially hydrogenated to tetralin over cobalt oxide or molybdenum oxide, then to decalin over ruthenium or iridium on carbon. The selectivity to cw-decalin is better than 90%. In a later phase of the synthesis 5-cyclododecen-l-one is hydrogenated over Raney nickel to obtain a mixture of cyclododecanone and cyclodode-canol in a combined yield of 90%. The selectivity of this step is not crucial since subsequent oxidation of either compound leads to the endproduct sebacic acid. 

Furan is readily hydrogenated, hence it is a source of commercial tetrahydrofuran (THF). Reaction with hydrogen sulfide over alumina produces thiophene. A recent patent describes a catalyst based on cobalt and molybdenum oxides supported on alumina for this reaction (105). Furan undergoes the Diels-Alder reaction with strong dienophiles. Hydrogenation of the product resulting from reaction with maleic anhydride, followed by hydrolysis and neutralization gives a herbicide, Endothall. 

Detailed adsorption studies by Morales and co-workers (Morales and Galiasso, 1982 Andreu et al., 1981 Morales et al., 1984) are unique in their examination of the interaction of VO-porphyrins extracted from Boscan crude on y-ALOrSupported cobalt and molybdenum catalysts. Interaction with the oxide catalyst is primarily through the oxygen ligand of... 

Molybdenum oxide - alumina systems have been studied in detail (4-8). Several authors have pointed out that a molybdate surface layer is formed, due to an interaction between molybdenum oxide and the alumina support (9-11). Richardson (12) studied the structural form of cobalt in several oxidic cobalt-molybdenum-alumina catalysts. The presence of an active cobalt-molybdate complex was concluded from magnetic susceptibility measurements. Moreover cobalt aluminate and cobalt oxide were found. Only the active cobalt molybdate complex would contribute to the activity and be characterized by octahedrally coordinated cobalt. Lipsch and Schuit (10) studied a commercial oxidic hydrodesulfurization catalyst, containing 12 wt% M0O3 and 4 wt% CoO. They concluded that a cobalt aluminate phase was present and could not find indications for an active cobalt molybdate complex. Recent magnetic susceptibility studies of the same type of catalyst (13) confirmed the conclusion of Lipsch and Schuit. 

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