摘要:
Provided is a process for preparing a non-pyrophoric catalyst having about 2 to 20 wt. % of a copper component, wherein at least 50 wt. % of the copper component is in the form of a copper oxide, aluminum oxide-spinel. The catalyst can be prepared by forming a mixture of a copper precursor and an alumina precursor, coextruding the mixture, drying the coextrudate and calcining the dried coextrudate at a temperature of at least 600° C. In other aspects, the invention also relates to processes for the activation of copper-based catalysts and for the regeneration of deactivated copper-based catalysts.
摘要:
The invention provides processes for selectively oxidizing carbon monoxide from an input gas stream that contains carbon monoxide, oxygen and hydrogen. The process includes the step of contacting the input gas stream with a preferential oxidation catalyst. The preferential oxidation catalysts are copper-based catalysts containing low concentrations of platinum group metals. In some embodiments, the processes of the invention are conducted using preferential oxidation catalysts having an oxide support on which is dispersed copper or an oxide thereof, a platinum group metal and a reducible metal oxide. In other embodiments, the processes of the invention are conducted with a preferential oxidation catalysts having a cerium oxide support on which is dispersed copper or an oxide thereof and a platinum group metal.
摘要:
Provided is a method and apparatus for producing hydrogen from an input gas stream containing carbon monoxide and steam that includes contacting the input gas stream with a catalyst. The catalyst contains an inorganic oxide support; a platinum group metal dispersed on the inorganic oxide support; and a methane suppressing dispersed on the inorganic oxide support. The methane suppressing component is selected from the group consisting of oxides of tin, oxides of gallium and combinations thereof. Also provided are preferred catalyst preparations.
摘要:
A water gas shift catalyst comprising a platinum group metal dispersed on an inorganic oxide support modified with a carbon-containing burn-out additive and a rare earth oxide. A water gas shift catalyst containing alumina, a platinum group metal, and oxides of Pr and Nd are also disclosed.
摘要:
A method for treating cooking fumes to oxidize oxidizeable particulate and gaseous components thereof includes contacting the fumes with a catalytic material containing ceria and alumina each having a BET surface of at least about 10 m.sup.2 /g, for example, ceria and activated alumina in a weight ratio of from about 1.5:1 and 1:1.5 and a BET surface area of from about 25 m.sup.2 /g to 200 m.sup.2 /g. Optionally, a catalytic metal component such as platinum or palladium may be included in the catalytic material. The foodstuffs cooking fumes are contacted with the catalyst composition (22 or 40) at a temperature of 200.degree. C. to 600.degree. C. to promote the oxidation of both particulate (atomized) animal and/or vegetable oils and fats and oxidizeable gas phase components of the fumes. Optionally, a separate, supplemental gas phase oxidation catalyst (42) may be used in conjunction with and downstream of the above-described catalyst (40) to provide a two-catalyst system for treating cooking fumes.
摘要:
A catalyst composition containing one or more binary oxides of palladium and rare earth metal such as Ce, La, Nd, Pr and/or Sm. The catalyst composition is used for the catalytic combustion of gaseous combustion mixtures of oxygen and carbonaceous fuels such as methane, e.g., a natural gas/air combustion mixture. Specific preferred binary oxides may be, for example, M.sub.2 O.sub.3.PdO (e.g., La.sub.2 O.sub.3.PdO) or 2M.sub.2 O.sub.3.PdO, wherein in each case M is La, Nd or Sm. A process of combusting gaseous carbonaceous fuels includes contacting a catalyst as described above under combustion conditions, e.g., 925.degree. C. to 1650.degree. C. and 1 to 20 atmospheres pressure, to carry out sustained combustion of the combustion mixture, including catalytically supported thermal combustion. Regeneration of over-temperatured M.sub.2 O.sub.3.PdO catalyst is also provided for.
摘要:
Oxidation catalyst compositions include a catalytic material containing ceria and alumina each having a surface area of at least about 10 m.sup.2 /g, for example, ceria and activated alumina in a weight ratio of from about 1.5:1 to 1:1.5. Optionally, platinum may be included in the catalytic material in amounts which are sufficient to promote gas phase oxidation of CO and HC but which are limited to preclude excessive oxidation of SO.sub.2 to SO.sub.3. Alternatively, palladium in any desired amount may be included in the catalytic material. The catalyst compositions have utility as oxidation catalysts for pollution abatement of exhausts contianing unburned fuel or oil. For example, the catalyst compositions may be used in a method to treat diesel engine exhaust by contacting the hot exhaust with the catalyst composition to promote the oxidation of the volatile organic fraction component of particulates in the exhaust.
摘要:
A method for operating a palladium oxide containing catalytic combustor useful, e.g., for powering a gas turbine, wherein the palladium oxide is supported on a metal oxide such as alumina, ceria, titania or tantalum oxide. The method involves maintaining control of the temperature within the combustor in such a manner as to insure the presence of palladium oxide. By maintaining the temperature below about 800.degree. C. decomposition of palladium oxide into metallic palladium is avoided and high catalytic activity is retained. Regeneration of catalyst following inactivation resulting from an over-temperature is accomplished by using a heat soak in a temperature range which varies depending on the metal oxide used to support the palladium oxide.
摘要:
Platinum-rhodium and platinum-palladium-rhodium gauzes bearing a high surface area coating (in excess of 50 cm.sup.2 /g) of platinum ease initiation of ammonia oxidation.