Activated alumina

About: Activated alumina is a research topic. Over the lifetime, 1430 publications have been published within this topic receiving 31090 citations.

Hydrogenation of fluoroacids with rhenium-fluorided alumina catalyst

Abstract: A fluoroacid is continuously hydrogenated to a corresponding alcohol by contact with a catalyst comprising at least one of rhenium and a hydrogen reducible rhenium compound supported on a fluorided alumina catalyst support. In one embodiment perfluorobutyric acid is catalytically reduced to 2,2,3,3,4,4,4-heptafluoro n-butanol employing a fluorided activated alumina impregnated with perrhenic acid.

Effect of MnCl 2 deposition content on the textural properties of activated alumina and its elution performance for hydrogen isotopes

Abstract: By a solution impregnation method, three modified stationary phases were prepared by contacting activated alumina with MnCl2 at different MnCl2:Al2O3 molar ratios = 1:10, 1:5, 1:2.5, respectively. N2 sorption isotherms at 78 K were examined for the unmodified and modified samples, from which pore size distributions (PSD) of textural properties were derived with density function theory. Elution chromatographic tests of hydrogen isotopes were carried out at 78 K. The results indicated that both the microporous specific surface area (SSA) and the mesoporous SSA decline after modification, while the microporous SSA remains nearly unvaried among the modified ones. The chromatographic retention times as well as the bandwidths decline as the Mn content rises. The resolution of chromatographic peaks increases after modification, it remains unvaried and then decreases as the Mn content increases. The PSD of alumina SSA changed by the modification significantly influences the hydrogen isotopic elution chromatography.

Preparation of oxygen-containing hydrocarbon compound from synthetic gas

Abstract: PURPOSE:To increase the catalytic activity in the preparation of acetic acid, acetaldehyde and/or ethanol by the reaction of CO with H2 in the presence of a Rh catalyst, by using Y and a metal selected from Zr, Ag, rare earth elements, etc. as cocatalyst. CONSTITUTION:Acetic acid, acetaldehyde and/or ethanol are prepared by reacting carbon monoxide with hydrogen in the presence of a catalyst composed of Rg and a cocatalyst components comprising Y and a metal selected from Zr, Ar, rare earth elements, U, Co, Ni and Th, at 220-350 deg.C under 20-200 atm. The catalyst can be prepared by dissolving the compounds of Rh and of the cocatalyst components in water or an organic solvent, adding a porous inorganic carrier substance (pref. silica, activated alumina, etc. having a specific surface area of 1-1,000m /g), and reducing or heat-treating the catalyst components. The content of Rh is pref. 0.1-10wt%, and that of the cocatalyst component is pref. 0.2-15wt%.

Prevention of air pollution by using activated alumina solid adsorbent to remove particulates of less than 0.5 microns from flue gases

Abstract: Particulates less than 0.5 microns in size are removed from flue gases by passing the flue gases into intimate contact with a solid adsorbent of activated alumina. The solid adsorbent is particularly useful in removing metal halide solids, e.g., AlCl3, KCl, NaCl, and AlF3, of less than 0.1 microns in size from the gaseous effluent of aluminum processing operations which utilize a gaseous chlorine treatment of molten aluminum.

A catalyst for reduction of emitted gases from automobile with lean-burn engine and the manufacturing method thereof

Abstract: PURPOSE: A catalyst for purifying exhaust gas of automobile with lean-burn engine is provided to efficiently purify nitrogen oxides that are not easily purified by existing catalysts for gasoline engine automobile under the rarefied combustion atmosphere as in the lean-burn engine automobile, and a manufacturing method thereof is provided. CONSTITUTION: The catalyst for purifying exhaust gas of automobile with lean-burn engine is characterized in that activated alumina, rare earth oxides and barium oxide (BaO) cocatalyst and precious metal catalyst activating material are respectively supported onto a ceramic or metallic porous support, wherein 30 to 50 wt.% of activated alumina is supported onto the support for 100 wt.% of the porous support, 1 to 5 wt.% of lanthanum (La) oxide, 10 to 30 wt.% of cerium (Ce) oxide and 10 to 20 wt.% of zirconium (Zr) oxide as the rare earth oxides are supported onto the support, and 5 to 20 wt.% of barium oxide (BaO) is supported onto the support for 100 wt.% of the porous support, and wherein the precious metal catalyst activating material is selected from platinum (Pt), palladium (Pd), rhodium (Rh), or a mixture thereof. The manufacturing method of the catalyst for purifying exhaust gas of automobile with lean-burn engine comprises a step (a) of mixing the materials after impregnating precious metal catalysts into activated alumina; a step (b) of preparing a slurry by adding rare earth oxides and barium oxide to the mixture and milling the materials; and a step (c) of drying and calcining the slurry coated porous support after coating the slurry prepared in the step (b) on a honeycomb monolith ceramic or metallic porous support.