Alumina-supported cobalt catalysts, hydrogen

Lee, D.-K., Lee, J.-H., and Ihm, S.-K. 1988. Effect of carbon deposits on carbon monoxide hydrogenation over alumina-supported cobalt catalysts. Appl. Catal. 36 199-207. 

Results of Hydrogen Chemisorption/Pulse Reoxidation Measurements over H2-activated Alumina-Supported Cobalt Catalysts Calcined at 350°C Using either Flowing Air or 5% Nitric Oxide in Nitrogen... 

Table 2 Experimental results on the influence of added water on the rate of CO hydrogenation over alumina-supported cobalt-catalysts. Reaction conditions 483 K, ratio H2 CO = 2.0-2.1 1, P — 20 bar (unless otherwise indicated)... 

Systematic assessment of alumina-supported cobalt-molybdenum nitride catalyst Relationship between nitriding conditions, innate properties and CO hydrogenation activity... 

Carbon Deposition Effects on CO Hydrogenation over Alumina-and Y Zeolite-supported Cobalt Catalysts S.-K. IhJn, D.-K. Lee... 

CARBON DEPOSITION EFFECTS IN CO HYDROGENATION OVER ALUMINA- AND Y ZEOLITE-SUPPORTED COBALT CATALYSTS... 

Y-Alumina supported unpromoted catalyst molybdenum sulphide and promoted catalysts cobalt sulphide - molybdenum sulphide nickel sulphide - molybdenum sulphide were prepared by Precipitation From Homogeneous Solution (PFHS) technique using thioacetamide hydrolysis in a single step. Oxygen chemisorption studies, hydrodesulphurisation (HDS) and hydrogenation (HYD) studies were made for these cat alyst s. These catalysts do not need pre-sulphidation prior to HDS reaction. 

Active heterogeneous catalysts have been obtained. Examples include titania-, vanadia-, silica-, and ceria-based catalysts. A survey of catalytic materials prepared in flames can be found in [20]. Recent advances include nanocrystalline Ti02 [24], one-step synthesis of noble metal Ti02 [25], Ru-doped cobalt-zirconia [26], vanadia-titania [27], Rh-Al203 for chemoselective hydrogenations [28], and alumina-supported noble metal particles via high-throughput experimentation [29]. 

Catalysts used for hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) of heavy oil fractions are largely based on alumina-supported molybdenum or tungsten to which cobalt or nickel is added as a promoter [11]. As the catalysts are active in the sulfided state, activation is carried out by treating the oxidic catalyst precursor in a mixture of H2S and H2 (or by exposing the catalyst to the sulfur-containing feed). The function of hydrogen is to prevent the decomposition of the relatively unstable H2S to elemental sulfur, which would otherwise accumulate on the surface of the... 

One of the characteristic features of the metal-catalysed reaction of acetylene with hydrogen is that, in addition to ethylene and ethane, hydrocarbons containing more than two carbon atoms are frequently observed in appreciable yields. The hydropolymerisation of acetylene over nickel—pumice catalysts was investigated in some detail by Sheridan [169] who found that, between 200 and 250°C, extensive polymerisation to yield predominantly C4 - and C6 -polymers occurred, although small amounts of all polymers up to Cn, where n > 31, were also observed. It was also shown that the polymeric products were aliphatic hydrocarbons, although subsequent studies with nickel—alumina [176] revealed that, whilst the main products were aliphatic hydrocarbons, small amounts of cyclohexene, cyclohexane and aromatic hydrocarbons were also formed. The extent of polymerisation appears to be greater with the first row metals, iron, cobalt, nickel and copper, where up to 60% of the acetylene may polymerise, than with the second and third row noble Group VIII metals. With alumina-supported noble metals, the polymerisation prod-... 

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