4070results about "Heterogenous catalyst chemical elements" patented technology

A process for selective formation of ethanol from acetic acid includes contacting a feed stream containing acetic acid and hydrogen at an elevated temperature with catalyst comprising platinum and tin on a high surface area silica promoted with calcium metasilicate. Selectivities to ethanol of over 85% are achieved at 280° C. with catalyst life in the hundreds of hours.

A two stage hydrodesulfurizing process for producing low sulfur distillates. A distillate boiling range feedstock containing in excess of about 3,000 wppm sulfur is hydrodesulfurized in a first hydrodesulfurizing stage containing one or more reaction zones in the presence of hydrogen and a hydrodesulfurizing catalyst. The liquid product stream thereof is passed to a first separation stage wherein a vapor phase product stream and a liquid product stream are produced. The liquid product stream, which has a substantially lower sulfur and nitrogen content then the original feedstream is passed to a second hydrodesulfurizing stage also containing one or more reaction zones where it is reacted in the presence of hydrogen and a second hydrodesulfurizing catalyst at hydrodesulfurizing conditions. The catalyst in any one or more reaction zones is a bulk multimetallic catalyst comprised of at least one Group VIII non-noble metal and at least two Group VIB metals.

Metal oxide catalysts comprising various dopants are provided. The catalysts are useful as heterogenous catalysts in a variety of catalytic reactions, for example, the oxidative coupling of methane to C2 hydrocarbons such as ethane and ethylene. Related methods for use and manufacture of the same are also disclosed.

Liquid feed flame spray pyrolysis of solutions of a metal oxide precursor which is an alkoxide or C_1-6 carboxylate and at least one second metal oxide precursor and/or second metal compound dissolved in oxygenated solvent by combustion with oxygen lead to the formation of sub-micron mixed-metal oxide powders not accessible by other processes or by the pyrolysis of metal chlorides or nitrates. The powders have numerous uses in advanced materials applications including particulate solid state lasers, advanced ceramic materials, and as catalysts in organic synthesis and automobile exhaust systems.

Disclosed is a catalyst. The catalyst comprises palladium, gold, and a support comprising titanium dioxide and tungsten trioxide. The support preferably comprises from 75 wt % to 99 wt % of titanium dioxide and from 1 wt % to 25 wt % of tungsten trioxide. A method for preparing the catalyst is also disclosed. The method comprises impregnating the support with a palladium compound and a gold compound, calcining the impregnated support, and then reducing the calcined support. Further disclosed is a method for preparing vinyl acetate with the catalyst. The catalyst exhibits improved catalytic activity and selectivity.

A method of manufacturing a porous sintered body includes mixing at least two groups of silicon carbide particles and a pore forming material having an average particle diameter Y μm to obtain a molding material. The at least two groups of silicon carbide particles have different average particle diameters and have a first group of silicon carbide particles whose blending quantity by weight in the molding material is greatest among the at least two groups of silicon carbide particles. The first group have an average particle diameter X μm. The relationships 15≦X, 0.5·X≦Z≦0.9·X, and 0.8·Z≦Y≦1.8·Z are satisfied, wherein Z μm is an average pore diameter of the porous sintered body no less than 10 μm and no greater than 20 μm.

Perovskite-type catalyst consists essentially of a metal oxide composition is provided. The metal oxide composition is represented by the general formula A.sub.1-x B.sub.x MO.sub.3, in which A is a mixture of elements originally in the form of single phase mixed lanthanides collected from bastnasite; B is a divalent or monovalent cation; M is at least one element selected from the group consisting of elements of an atomic number of from 22 to 30, 40 to 51, and 73 to 80; and x is a number defined by 0.ltoreq.x<0.5.

A catalyst composition and process facilitates the oxidative reforming of low molecular weight hydrocarbons, such as methane, to other hydrocarbons having 2 or more carbon atoms (“C₂₊ compounds”). Compositions having a formula comprising a metal, tungsten, manganese and oxygen effectively catalyze the oxidative reforming of methane with a high rate of conversion and selectivity. Controlling feed gas flow and catalyst bed temperature controls the exothermic OCM reaction, avoiding runaway reactions or coking. A single or multiple reactor system can be utilized for the oxidative reforming reactions. Using two reactors in series, catalyst embodiments produced favorable yields of C₂₊ compounds, in the presence or absence of a distributed oxygen feed, and with or without interstage effluent cooling. Removal of desirable end products from the reactor effluent, followed by recycling of the residual effluent, increases the conversion to, and ultimate yield of desirable end product.

A catalyst system and process for combined cracking and selective hydrogen combustion of hydrocarbons are disclosed. The catalyst system contains at least one solid acid component and at least one metal-based component which consists of (a) oxygen and/or sulfur and (b) a metal combination selected from the group consisting of: i) at least one metal from Group 3 and at least one metal from Groups 4-15 of the Periodic Table of the Elements; ii) at least one metal from Groups 5-15 of the Periodic Table of the Elements, and at least one metal from at least one of Groups 1, 2, and 4 of the Periodic Table of the Elements; iii) at least one metal from Groups 1 and 2, at least one metal from Group 3, and at least one metal from Groups 4-15 of the Periodic Table of the Elements; and iv) two or more metals from Groups 4-15 of the Periodic Table of the Elements, wherein the at least one of oxygen and sulfur is chemically bound both within and between the metals and, optionally, (3) at least one of at least one support, at least one filler and at least one binder. The process is such that the yield of hydrogen is less than the yield of hydrogen when contacting the hydrocarbons with the solid acid component alone. Further the emissions of NOx from the regeneration cycle of the catalyst system are reduced.

Metal oxide catalysts comprising various dopants are provided. The catalysts are useful as heterogenous catalysts in a variety of catalytic reactions, for example, the oxidative coupling of methane to C2 hydrocarbons such as ethane and ethylene. Related methods for use and manufacture of the same are also disclosed.

An inorganic material that consists of at least two elementary spherical particles, each of said spherical particles comprising metal nanoparticles that are between 1 and 300 nm in size and a mesostructured matrix with an oxide base of at least one element X that is selected from the group that consists of aluminum, titanium, tungsten, zirconium, gallium, germanium, tin, antimony, lead, vanadium, iron, manganese, hafnium, niobium, tantalum, yttrium, cerium, gadolinium, europium and neodymium is described, whereby said matrix has a pore size of between 1.5 and 30 nm and has amorphous walls with a thickness of between 1 and 30 nm, said elementary spherical particles having a maximum diameter of 10 μm. Said material can also contain zeolitic nanocrystals that are trapped within said mesostructured matrix.

The exhaust gas of internal combustion engines operated with a predominantly stoichiometric air/fuel mixture contains, as well as the gaseous hydrocarbon (HC), carbon monoxide (CO) and nitrogen oxide (NO_x) pollutants, also ultrafine particulates. The introduction of the EU-5 exhaust gas standard in Europe in 2010 will for the first time impose a legal limit to these particulate emissions for gasoline vehicles. Future exhaust gas cleaning concepts for these vehicles must include devices for removing these particulates.

A catalytically active particulate filter, an exhaust gas cleaning system and a process for cleaning the exhaust gases of predominantly stoichiometrically operated internal combustion engines are presented, which are suitable, as well as the gaseous CO, HC and NO_x pollutants, also for removing particulates from the exhaust gas. The particulate filter comprises a filter body and a catalytically active coating consisting of two layers. Both layers contain alumina. The first layer contains palladium. The second layer contains rhodium. The latter is disposed above the first layer.

There is disclosed a production process for a catalyst which process makes it possible to efficiently carry out the supporting of a catalytic component onto a carrier and to obtain the catalyst excellent in quality and performance. This production process is a production process for the catalyst including a particulate lump carrier and a catalytic component supported thereon; with the production process comprising the step of carrying out simultaneous revolution and rocking of a treatment container 20 as charged with the carrier and a catalyst precursor including the catalytic component, thereby supporting the catalytic component onto the carrier.

Composite hydrogen transport membranes, which are used for extraction of hydrogen from gas mixtures are provided. Methods are described for supporting metals and metal alloys which have high hydrogen permeability, but which are either too thin to be self supporting, too weak to resist differential pressures across the membrane, or which become embrittled by hydrogen. Support materials are chosen to be lattice matched to the metals and metal alloys. Preferred metals with high permeability for hydrogen include vanadium, niobium, tantalum, zirconium, palladium, and alloys thereof. Hydrogen-permeable membranes include those in which the pores of a porous support matrix are blocked by hydrogen-permeable metals and metal alloys, those in which the pores of a porous metal matrix are blocked with materials which make the membrane impervious to gases other than hydrogen, and cermets fabricated by sintering powders of metals with powders of lattice-matched ceramic.

A co-catalyst for purifying an exhaust gas which can be used for a loner period of time as an actual catalyst by using the cerium oxide in the conventional co-catalyst for purifying the exhaust gas as a cerium-containing complex oxide for elevating the resistance to heat and suppressing the performance reduction due to thermal deterioration and by making a specific surface area and an oxygen storage capacity over specified values. A co-catalyst for purifying an exhaust gas of the present invention includes a composite oxide including (a) cerium; and (b) at least one element selected from the group consisting of zirconium, yttrium, strontium, barium and a rare-earth element supported on a particulate aluminum oxide support; a specific surface area of the co-catalyst after sintering being not less than 40 m2/g; an oxygen storage capacity at 400° C. being not less than 10 mumols/g and an oxygen storage capacity at 700° C. being not less than 100 mumols/g.

A high exhaust gas-purifying efficiency is achieved. An exhaust gas-purifying catalyst includes a substrate, an oxygen storage layer covering the substrate and including an oxygen storage material, and a catalytic layer covering the oxygen storage layer and including palladium, rhodium and a carrier supporting them, the catalytic layer having a precious metal concentration higher than that of the oxygen storage layer.

The invention relates to a catalyst for catalyzing and oxidizing waste water under normal temperature and normal pressure. The catalyst comprises active carbon, oxide of Fe and oxides of any two, three or four elements selected from Cu, Zn, Mn, Co, Ni or Ce, wherein the active carbon is used as a carrier, the oxide of Fe is used as a primary active component, and the oxides of any two, three or four elements selected from Cu, Zn, Mn, Co, Ni or Ce are used as secondary active components. The invention also relates to a preparation method of the catalyst.

Disclosed herein is a method for producing monohydric alcohols from monocarboxylic acids or derivatives thereof using a catalyst comprising ruthenium (Ru) and tin (Sn) using zinc oxide (ZnO) as both a catalyst support and an active promoter; a catalyst prepared by adding an inorganic binder such as silica, alumina or titania in a limited range to the catalyst comprising the above components in order to impart a shaping ability to the catalyst; or, a modified catalyst reformed by adding at least one reducing component selected from the group consisting of Co, Ni, Cu, Ag, Rh, Pd, Re, Ir, and Pt to the catalyst in order to improve the reducing ability of the catalyst. By using such catalysts, the method according to the present invention is advantageous in that the monohydric alcohols can be prepared in high yield regardless of whether the monocarboxylic acids contain water or not, the monohydric alcohols can be economically prepared because the catalysts can be operated under mild reaction conditions and also exhibits high selectivity and productivity compared to conventional catalysts, and the catalysts have excellent long-term reaction stability so as to be advantageous for industrial applications.

A method of producing a porous composite metal oxide comprising the steps of: dispersing first metal oxide powder, which is an aggregate of primary particles each with a diameter of not larger than 50 nm, in a dispersion medium by use of microbeads each with a diameter of not larger than 150 μm, thus obtaining first metal oxide particles, which are 1 nm to 50 nm in average particle diameter, and not less than 80% by mass of which are not larger than 75 nm in diameter; dispersing and mixing up, in a dispersion medium, the first metal oxide particles and second metal oxide powder, which is an aggregate of primary particles each with a diameter of not larger than 50 nm, and which is not larger than 200 nm in average particle diameter, thus obtaining a homogeneously-dispersed solution in which the first metal oxide particles and second metal oxide particles are homogeneously dispersed; and drying the homogeneously-dispersed solution, thus obtaining a porous composite metal oxide.

A catalyst for producing from an olefin the corresponding unsaturated aldehyde and unsaturated carboxylic acid in high yield; and a process for producing the catalyst. The process is for producing a composite oxide catalyst which is for use in catalytically oxidizing an olefin in a vapor phase with a gas containing molecular oxygen to produce the corresponding unsaturated aldehyde and corresponding unsaturated carboxylic acid, and which comprises (A) molybdenum, (B) bismuth, (C) cobalt and/or nickel, and (D) iron. It is characterized in that catalyst precursor particles produced through a preceding step in which an aqueous dispersion containing a raw material for the ingredient (A), raw material for the ingredient (C), and raw material for the ingredient (D) which have been united with one another and having a nitric acid radical content satisfying the relationship 1.2<=NO3/(3xFe+2x(Co+Ni)) is dried and then heated are united with a raw material for the ingredient (B) in a water-miscible solvent and the resultant united matter is dried and burned. In the relationship, NO3, Fe, Co, and Ni indicate the molar contents of nitric acid radicals, iron, cobalt, and nickel, respectively.

A catalyst precursor composition and methods for making such catalyst precursor is disclosed. In one embodiment, the catalyst precursor is of the general formula A_v[(M^P)(OH)_x(L)ⁿ_y]_z(M^VIBO₄), wherein M^P is selected from Group VIII, Group IIB, Group IIA, Group IVA and combinations thereof; L is one or more oxygen-containing ligands, and L has a neutral or negative charge n<=0, M^VIB is at least a Group VIB metal having an oxidation state of +6; M^P:M^VIB has an atomic ratio between 100:1 and 1:100; v−2+P*z−x*z+n*y*z=0; and 0≦y≦−P/n; 0≦x≦P; 0≦v≦2; 0≦z. In one embodiment, the catalyst precursor further comprises a cellulose-containing material. In another embodiment, the catalyst precursor further comprises at least a diluent (binder). In one embodiment, the diluent is a magnesium aluminosilicate clay.

A homogeneous ceria-based mixed-metal oxide, useful as a catalyst support, a co-catalyst and/or a getter, is described. The mixed-metal oxide has a relatively large surface area per weight, typically exceeding 150 m<2>/g, a structure of nanocrystallites having diameters of less than 4 nm, and including pores larger than the nanocrystallites and having diameters in the range of 4 to about 9 nm. The ratio of the pore volumes, VP, to skeletal structure volumes, VS, is typically less than about 2.5, and the surface area per unit volume of the oxide material is greater than 320 m<2>/cm<3>, such that the structural morphology supports both a relatively low internal mass transfer resistance and large effective surface area for reaction activity of interest. The mixed metal oxide is made by co-precipitating a dilute metal salt solution containing the respective metals, which may include Zr, Hf, and/or other metal constituents in addition to Ce, replacing water in the co-precipitate with a water-miscible low surface-tension solvent, and relatively quickly drying and calcining the co-precipitate at moderate temperatures. A highly dispersive catalyst metal, such as Pt, may be loaded on the mixed metal oxide support from a catalyst-containing solution following a selected acid surface treatment of the oxide support. The mixed metal oxide, as catalyst support, co-catalyst or getter, is applied in various reactions, and particularly water gas shift and/or preferential oxidation reactions as associated with fuel processing systems, as for fuel cells and the like.

The present invention relates to thermally stable supports and catalysts for use in high temperature operation, and methods of preparing such supports and catalysts, which includes adding a rare earth metal to an aluminum-containing precursor prior to calcining. The present invention can be more specifically seen as a support, process and catalyst wherein the thermally stable support comprises two rare earth aluminates of different molar ratios of aluminum to rare earth metal, and optionally, alumina and/or a rare earth oxide. More particularly, the invention relates to the use of noble metal catalysts comprising the thermally stable support for synthesis gas production via partial oxidation of light hydrocarbon (e.g., methane) with minimal deactivation over long-term operations and further relates to gas-to-liquids conversion processes.

A catalyst and a method for selectively reducing nitrogen oxides (“NO_x”) with ammonia are provided. The catalyst includes a first component comprising a zeolite or mixture of zeolites selected from the group consisting of ZSM-5, ZSM-11, ZSM-12, ZSM-18, ZSM-23, MCM-zeolites, mordenite, faujasite, ferrierite, zeolite beta, and mixtures thereof; a second component comprising at least one member selected from the group consisting of cerium, iron, copper, gallium, manganese, chromium, cobalt, molybdenum, tin, rhenium, tantalum, osmium, barium, boron, calcium, strontium, potassium, vanadium, nickel, tungsten, an actinide, mixtures of actinides, a lanthanide, mixtures of lanthanides, and mixtures thereof; optionally an oxygen storage material and optionally an inorganic oxide. The catalyst selectively reduces nitrogen oxides to nitrogen with ammonia at high temperatures. The catalyst has high hydrothermal stability. The catalyst has high activity for conversion of low levels of nitrogen oxides in exhaust streams. The catalyst and the method may have special application to selective reduction of nitrogen oxides in exhaust gas from gas turbines and gas engines, although the catalyst and the method have broad application to a wide range of gas streams that have excess oxygen and high temperatures. The temperature of exhaust gas from gas turbines and gas engines is high. Both the high temperature and the low levels of inlet NO_x are challenging for selective catalytic reduction (SCR) catalysts.

A mixed metal oxide Mo-V-Ga-Pd-Nb-X (where X=La, Te, Ge, Zn, Si, In or W) catalytic system providing a higher selectivity to acrylic acid in the low temperature partial oxidation of propane with a molecular oxygen-containing gas.

A multi-phase catalyst for the simultaneous conversion of oxides of nitrogen, carbon monoxide, and hydrocarbons is provided. A catalyst composition comprising the multi-phase catalyst and methods of making the catalyst composition are also provided. The multi-phase catalyst may be represented by the general formula of Ce_yLn_1-xA_x+sMO_Z, wherein Ln is a mixture of elements originally in the form of single-phase mixed lanthanides collected from natural ores, a single lanthanide, or a mixture of lanthanides; A is an element selected from a group consisting of Mg, Ca, Sr, Ba, Li, Na, K, Cs, Rb, or any combination thereof; and M is an element selected from the group consisting of Fe, Mn, Cr, Ni, Co, Cu, V, Zr, Pt, Pd, Rh, Ru, Ag, Au, Al, Ga, Mo, W, Ti, or any combination thereof; x is a number defined by 0≦x<1.0; y is a number defined by 0≦y<10; s is a number defined by 0≦s<10; where s=0 only when y>0 and y=0 only when s>0. The multi-phase catalyst can have an overlayer of an oxide having the fluorite structure with a combination of platinum and/or rhodium.

The invention generally relates to three-way catalysts and catalyst formulations capable of simultaneously converting nitrogen oxides, carbon monoxide, and hydrocarbons into less toxic compounds. Such three-way catalyst formulations contain ZrO₂-based mixed-metal oxide support oxides doped with an amount of lanthanide. Three-way catalyst formulations with the support oxides of the present invention demonstrate higher catalytic activity, efficiency and longevity than comparable catalysts formulated with traditional support oxides.

The present invention relates to a novel composite metal oxide catalyst, a method of making the catalyst, and a process for producing synthesis gas using the catalyst. The catalyst may be a nickel and cobalt based dual-active component composite metal oxide catalyst. The catalyst may be used to produce synthesis gas by the carbon dioxide reforming reaction of methane. The catalyst on an anhydrous basis after calcinations has the empirical formula:

M^m+ and Nⁿ⁺ are two transition metals serving as dual-active components and selected from the group consisting of Ni, Co, Fe, Mn, Mo, Cu, Zn or mixtures thereof, a+b+c+d=1, and 0.001≦a≦0.8, 0.001≦b≦0.8, 0.1≦c≦0.99, 0.01≦d≦0.99.

Disclosed herein is a catalytically active particulate filter, an exhaust gas cleaning system and a process for cleaning the exhaust gases of predominantly stoichiometrically operated internal combustion engines, which are suitable, as well as the gaseous CO, HC and NO_x pollutants, also for removing particulates from the exhaust gas. The particulate filter comprises a filter body and a catalytically active coating consisting of two layers. The first layer is in contact with the incoming exhaust gas, the second layer with the outgoing exhaust gas. Both layers contain alumina. The first layer contains palladium. The second layer contains, in addition to rhodium, an oxygen-storing cerium/zirconium mixed oxide.

The invention relates to materials used as electrodes and/or catalysts, as well as methods associated with the same. The materials may comprise an alloy or intermetallic compound of a transition metal (e.g., Ni) and a metal additive (e.g., Sn). The transition metal and additive are selected to provide improved electrode and/or catalytic performance. For example, the materials of the invention may have a high catalytic activity, while being less susceptible to coking than certain conventional electrode/catalytic materials. These performance advantages can simplify the equipment used in certain applications, as well as reducing energy and capital requirements. Furthermore, the materials may be manufactured using traditional ceramic processing methods, without the need for complex, unconventional fabrication techniques. The materials are particularly suitable for use in fuel cells (e.g., SOFCs electrodes) and in reactions that use or produce synthesis gas.