25441results about "Molecular sieve catalysts" patented technology

A process for selective formation of ethylene from acetic acid includes contacting a feed stream containing acetic acid and hydrogen at an elevated temperature with a first catalytic composition including a suitable hydrogenating catalyst in a first reaction zone to form an intermediate mixture including ethanol and ethyl acetate; and subsequently reacting the intermediate mixture over a suitable dehydrating and / or cracking catalyst in a second reaction zone to form ethylene. Selectivities of ethylene of over 80% are achieved.

Provided is an emission treatment system and method for simultaneously remediating the nitrogen oxides (NOx), particulate matter, and gaseous hydrocarbons present in diesel engine exhaust streams. The emission treatment system has an oxidation catalyst upstream of a soot filter coated with a material effective in the Selective Catalytic Reduction (SCR) of NOx by a reductant, e.g., ammonia. Also provided is a method for disposing an SCR catalyst composition on a wall flow monolith that provides adequate catalyst loading, but does not result in unsuitable back pressures in the exhaust.

Zeolite catalysts and systems and methods for preparing and using zeolite catalysts having the CHA crystal structure are disclosed. The catalysts can be used to remove nitrogen oxides from a gaseous medium across a broad temperature range and exhibit hydrothermal stable at high reaction temperatures. The zeolite catalysts include a zeolite carrier having a silica to alumina ratio from about 15:1 to about 256:1 and a copper to alumina ratio from about 0.25:1 to about 1:1.

The invention discloses and belongs to the chemical equipment field, which more particularly relates to a C1-C2 hydrocarbon or methanol aromatization and catalyst regeneration fluidized bed device (comprising an aromatization fluidized bed, a catalyst continuous regeneration fluidized bed, a pipeline used for catalyst transportation and a solid transportation device which are arranged between the two fluidized beds), and an aromatization catalyst which is suitable for the fluidized bed operations and the operation methods of aromatization reaction, catalyst regeneration and the device. The device, the catalyst and the method are used for regulating the coking status of the catalyst in an aromatization reactor at any time, thus achieving the aim of transforming the C1-C2 hydrocarbon or the methanol continuously and efficiently and generating aromatics with high selectivity. The C1-C2 hydrocarbon or methanol aromatization and catalyst regeneration fluidized bed device of the invention with adjustable catalyst activity and selectivity can improve the purity and yield of the aromatics, can lead the aromatization reactor operates continuously without stopping at the same time, can improve the strength of aromatics production, and lower the operation cost of the catalyst regeneration when stopping and restarting the whole system.

There is described a process and a catalyst for the hydroalkylation of an aromatic hydrocarbon, particularly benzene, wherein the catalyst comprises a first metal having hydrogenation activity and a crystalline inorganic oxide material having a X-ray diffraction pattern including the following d-spacing maxima 12.4±0.25, 6.9±0.15, 3.57±0.07 and 3.42±0.07.

The present invention is directed to a diesel oxidation catalyst for the treatment of exhaust gas emissions, such as the oxidation of unburned hydrocarbons (HC), and carbon monoxide (CO) and the reduction of nitrogen oxides (NOx). More particularly, the present invention is directed to a novel washcoat composition comprising two distinct washcoat layers containing two distinctly different ratios of Pt:Pd.

A method to promote the activity of a catalyst for dehydrogenation of propane to propylene is as follows: (1) an inorganic oxide bonding agent, a promoter and an acid solvent are added into a heat-resistant oxide; then after the oxide bonding agent, the promoter, the acid solvent and the oxide are kneaded evenly, the oxide is molded by rolling or band-extruding; (2) the catalyst carrier prepared is dried for 2 to 10 hours under the temperature of 60 centigrade degrees, and calcined under the temperature of 400 to 800 degrees; (3) the calcined carrier is immersed in a rare earth metal water solution under the temperature of 60 to 100 centigrade degrees for 2 to 10 hours; (4) the catalyst carrier modified by the rare earth is immersed in a water solution comprising platinum metal elementsand the fourteenth metal elements under the temperature of 400 to 600 centigrade degrees for 2 to 10 hours, and then the carrier is filtered, washed with distilled water, dried under the temperature of 60 to 180 centigrade degrees for 2 to 10 hours, and calcined under the temperature of 400 to 600 centigrade degrees for 2 to 10 hours; (5) the catalyst prepared is activated in the air under the temperature of 400 to 600 centigrade degrees for 3 to 10 hours, and reduced in a hydrogen flow under the temperature of 400 to 600 centigrade degrees for 2 to 10 hours; the reduced catalyst is used for catalytic reaction for dehydrogenation of propane to propylene.

The present invention pertains to catalyst systems for nitrogen oxide, carbon monoxide, hydrocarbon, and sulfur reactions that are free or substantially free of platinum group metals. The catalyst system of the present invention comprise a substrate and a washcoat, wherein the washcoat comprises at least one oxide solid, wherein the oxide solid comprises one or more selected from the group consisting of a carrier material oxide, a catalyst, and mixtures thereof. The catalyst system may optionally have an overcoat, wherein the overcoat comprises at least one oxide solid, wherein the oxide solid comprises one or more selected from the group consisting of a carrier material oxide, a catalyst, and mixtures thereof. The catalyst comprises one or more selected from the group consisting of a ZPGM transition metal catalyst, a mixed metal oxide catalyst, a zeolite catalysts, or mixtures thereof.

A composite material comprises: (a) a porous crystalline inorganic oxide material comprising a first framework structure defining a first set of uniformly distributed pores having an average cross-sectional dimension of from 0.3 to less than 2 nanometers and comprising a second framework structure defining a second set of uniformly distributed pores having an average cross-sectional dimension of from 2 to 200 nanometers and (b) a co-catalyst within the second set of pores of the porous crystalline inorganic oxide material (a).