Cobalt Alumina Catalysts Research Articles

Conversion of 2-octanol over nickel-alumina, cobalt-alumina, and alumina catalysts

Structural characterization of CoAl and NiAl coprecipitated catalysts has been accomplished using techniques such as X-ray diffraction, DTA, TGA, TG-MS, BET surface area and pore volume. The catalyst samples were prepared by coprecipitation of cobalt (or nickel) and aluminum from their aqueous salt solutions. The interaction of Co (or Ni) with aluminum has been investigated by X-ray diffraction as a function of calcination temperature. The results indicate that the interaction between Co and Al can lead to the formation of a normal spinel of CoAl 2O 4 at a very low temperature such as 473 K. On the other hand the interaction between Ni and Al is not sufficient to form well crystallized NiAl 2O 4 species at low temperatures but nickel-aluminate formation was seen above 973 K. The activity and selectivity of these catalysts for 2-octanol conversion are dependent on the reaction temperature, liquid hour space velocity (LHSV) as well as on the calcination temperature. The dehydrogenation activity of nickel based catalysts is attributed to the presence of nickel oxide whereas the dehydration activity is due to the spinel phase. The differences in the dehydration activity between alumina and nickel-alumina is mostly because of the incomplete formation of spinel phase (i.e., low temperature calcined samples). Catalytic activity of cobalt-alumina catalysts is comparable with that of alumina catalysts towards 2-octanol conversion.

ChemInform Abstract: Hydrocracking of Cyclohexane and Methylcyclopentane over a Cobalt‐Alumina Catalyst.

Chemischer InformationsdienstVolume 17, Issue 46 Preparative Organic Chemistry ChemInform Abstract: Hydrocracking of Cyclohexane and Methylcyclopentane over a Cobalt-Alumina Catalyst. M. OBA, M. OBASearch for more papers by this authorY. MIKI, Y. MIKISearch for more papers by this authorS. YAMADAYA, S. YAMADAYASearch for more papers by this authorY. SUGIMOTO, Y. SUGIMOTOSearch for more papers by this author M. OBA, M. OBASearch for more papers by this authorY. MIKI, Y. MIKISearch for more papers by this authorS. YAMADAYA, S. YAMADAYASearch for more papers by this authorY. SUGIMOTO, Y. SUGIMOTOSearch for more papers by this author First published: November 18, 1986 https://doi.org/10.1002/chin.198646096AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume17, Issue46November 18, 1986 RelatedInformation

The influence of zinc on the surface properties of cobalt-alumina catalysts

Addition of a small quantity of zinc to γ-Al 2O 3 was studied with respect to influence on the surface properties of a series of Co Al 2O 3 catalysts. ESCA and ISS results indicate that at low cobalt concentrations (≤8% Co) the presence of zinc can enhance formation of a cobalt “surface spinel” resulting from the diffusion of Co ions into tetrahedral sites of the γ-Al 2O 3 support. At higher cobalt loadings a drastic increase in the ESCA and ISS metal/support intensity ratios is seen relative to catalysts without zinc. X-Ray diffraction data indicate that the increases in intensity ratios result from an increase in dispersion, i.e., generation of smaller cobalt oxide crystallites in the zinc-doped catalysts. For a series of catalysts having fixed cobalt concentrations, the influence of particle size on ESCA and ISS intensity ratios was determined.

Surface spectroscopic characterization of cobalt-alumina catalysts

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSurface spectroscopic characterization of cobalt-alumina catalystsRoland L. Chin and David M. HerculesCite this: J. Phys. Chem. 1982, 86, 3, 360–367Publication Date (Print):February 1, 1982Publication History Published online1 May 2002Published inissue 1 February 1982https://doi.org/10.1021/j100392a016RIGHTS & PERMISSIONSArticle Views487Altmetric-Citations187LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (1 MB) Get e-Alerts

Catalytic reduction of NO with hydrogen over a cobalt-alumina catalyst effect of alkali metal additives

The process was carried out over Co/Al catalysts containing oxides of alkali metals (Li, Na, Rb, Cs) as additives. The presence of alkali metals generally decreases the activity of the Co/Al catalysts, except for very low concentrations of Li, Na, Rb and Cs atoms. Activity of catalyst increases with atomic weight of alkali metal additive. Possible effect of additive on catalyst structure is briefly discussed with respect to catalyzed process.

Catalytic reduction of NO with H2 and CO over cobalt-alumina and chromium-alumina catalysts

The catalytic reduction of NO with H2 and CO has been studied over Co/Al and Cr/Al catalysts prepared by coprecipitation. The data show a much larger difference in the activities of Cr/Al and Co/Al when reducing NO with CO than in the case of H2. In both cases Cr/Al appears to be much more selective to N2 formation than Co/Al. The dependence of the selectivity on temperature is different for the two reductants on the Co/Al catalyst. The results suggest that most of the N2O desorbs from the surface of the Co/Al catalyst before N2 is formed.

Infrared spectra of nitric oxide adsorbed on cobalt-alumina catalyst

Nitric oxide adsorption on the surface of a Co−Al catalyst was investigated using infrared technique. The presence of two kinds of adsorbed species was confirmed by N−O stretching frequencies at 1780 and 1855 cm−1. The effect of potassium added to the Co−Al catalyst was examined.

Catalytic reduction of nitric oxide with hydrogen over a cobalt-alumina catalyst. The effect of potassium additives

Catalytic reduction of NO with hydrogen has been studied using a differential reactor operated at atmospheric pressure. The process was carried out over a Co/Al catalyst containing potassium oxide as an additive. The presence of potassium generally produces a decrease in activity of the Co/Al catalyst except for very low concentrations of potassium atoms.

Catalytic conversions of spiro[4,5 ]decane on platinum-alumina, palladium-alumina, and cobalt-alumina catalysts under catalytic reforming conditions

1. The conversions of spiro[4,5]decane on 0.5% platinum-alumina, 0.5% palladium-alumina, and 10% cobalt-alumina catalysts at 450° and a hydrogen pressure of 30 atm have been investigated. 2. Under these conditions the main reaction is the isomerization of the spirane to naphthalene. This takes place most readily on the platinum catalyst. 3. Rupture of the five-membered ring of the spirodecane and all the C-C bonds also takes place with the formation of small amounts of gem-disubstituted cyclohexanes and alkylbenzenes.

Kinetics of the Hydrogenation of Aniline in the Vapor Phase on a Cobalt-Alumina Catalyst

Abstract The kinetics of the catalytic hydrogenation of aniline with a cobalt-alumina catalyst in the temperature range from 160° to 210°C was studied by a differential flow reactor with a fixed bed. (1) The rate of reaction reaches a maximum in the 180–190°C range for the hydrogenation of aniline. From the thermodynamic calculations and the experimental results for a fluidized-bed reactor, the reverse reaction was found to be almost negligible below 200°C under the conditions of the reaction. This phenomenon was explained by the proposed kinetics of the reaction. (2) The initial rate of reaction without cyclohexylamine, and the rate when some cyclohexylamine was added to the reactants, were measured at atmospheric pressure over the following range of conditions of partial pressures; hydrogen 0.3–0.92 atm., aniline 0.05–0.2 atm., cyclohexylamine 0–0.24 atm. It was concluded that a plausible rate-controlling step was the surface reaction, i. e., the reaction between the adsorbed aniline and hydrogen on the surface of the catalyst. The equation for the vapor phase hydrogenation of aniline on a cobalt-alumina catalyst in the temperature range from 150°C to 210°C was determined to be: r=k\fracKH3KAPH3PA(1+KHPH+KAPA+KCPC)4