A catalyst article having an extruded support having a plurality of channels through which exhaust gas flows during operation of an engine, and a single layer coating or a bi-layer coating on the support, where the extruded support contains a third SCR catalyst, the single layer coating and the bilayer-coating contain platinum on a support with low ammonia storage and a first SCR catalyst. The catalytic articles are useful for selective catalytic reduction (SCR) of NOx in exhaust gases and in reducing the amount of ammonia slip. Methods for producing such articles are described. Methods of using the catalytic articles in an SCR process, where the amount of ammonia slip is reduced, are also described.

Processes for forming multimetallic catalysts by grafting nickel precusors to metal oxide supports. Dry reforming reaction catalysts having nickel and promotors grafted to metal oxides supports. Methanation reaction catalysts having nickel and promotors grafted to metal oxides supports.

A catalyst for hydrocarbon catalytic cracking of the invention contains: a catalyst (a) containing faujasite-type zeolite (A) having a unit cell size in a range of 2.435 nm to 2.455 nm, a matrix component, and rare earths; and a catalyst (b) containing faujasite-type zeolite (B) having a unit cell size in a range of 2.445 nm to 2.462 nm, a matrix component, phosphorus, and magnesium.

Disclosed are a ferrite catalyst and preparation methods thereof. The catalyst is provided with a formula below, wherein A is Mg atom, Zn atom or a mixture of both atoms at any ratio; D is one or more atoms selected from the group consisting of Ni, Co, W, Mn, Ca, Mo or V atom; Z is a catalyst carrier, which is one or more selected from the group consisting of calcium phosphate, calcium dihydrogen phosphate, aluminum phosphate, aluminum dihydrogen phosphate, ferric phosphate, magnesium phosphate, zinc phosphate, Mg—Al hydrotalcite, calcium carbonate, magnesium carbonate; a=0.01-0.6; b=0-0.30; c is a number balancing each valence; x, y represent the amounts of principal catalyst and carrier Z respectively, wherein the weight ratio y/x=0.5:1-7:1.
x(FeA.sub.aD.sub.bO.sub.c)/yZ

The present invention relates to a method for producing a carbon nanotube aggregate whose bulk density is easily controllable. Therefore, the present invention provides a carbon nanotube aggregate suitable for use in various fields.

The invention relates to a catalyst for preparation of butadiene by oxydehydrogenation of butene in a fluidized bed reactor, a method of preparing the same, and use of the same, wherein a method according to an embodiment of the invention comprises: reacting a metal precursor with an alkaline substance to obtain a slurry containing insoluble compound, followed by filtering and washing the slurry; adding a binder and deionized water, followed by agitation to regulate the solid content of the slurry to 10-50%; subjecting the slurry to spray drying granulation, wherein the temperature at the feed port is controlled between 200-400° C., and the temperature at the discharge port is controlled between 100-160° C., to obtain catalyst microspheres; and drying the catalyst microspheres at 80-200° C. for 1-24 h, and then calcining the catalyst microspheres at 500-900° C. for 4-24 h to obtain a catalyst having a general formula of FeXaYbZcOd, comprising Fe, Mg, Zn, Bi, Mo, Mn, Ni, Co, Ba, Ca, and other metals. The catalyst microspheres prepared according to the exemplary method exhibit high mobility, desirable particle size distribution, extremely high mechanical strength and catalytic activity, and are applicable to industrial production of butadiene by oxydehydrogenation of butene in a fluidized bed. When this catalyst is used to prepare butadiene by oxydehydrogenation of butene, the yield of butadiene is 76-86%, and the selectivity to butadiene is 94-97%.

This exhaust gas purifying catalyst is provided with a substrate and a catalyst layer formed on a surface of the substrate. The catalyst layer contains zeolite particles that support a metal, and a rare earth element-containing compound that contains a rare earth element. The rare earth element-containing compound is added in such an amount that the molar ratio of the rare earth element relative to Si contained in the zeolite is 0.001 to 0.014 in terms of oxides.

This exhaust gas purifying catalyst is provided with a substrate 10 and a catalyst layer 20 formed on a surface of the substrate 10. The catalyst layer 20 contains zeolite particles 22 that support a metal, and a rare earth element-containing compound 24 that contains a rare earth element. The rare earth element-containing compound 24 is added in such an amount that the molar ratio of the rare earth element relative to Si contained in the zeolite 22 is 0.001 to 0.014 in terms of oxides.

Provided is a nitrogen oxide (NO.sub.X) reduction catalyst including an active site including at least one of a metal vanadate expressed by [Chemical Formula 1] and a metal vanadate expressed by [Chemical Formula 2], and a support for loading the active site thereon.
(M.sub.1).sub.XV.sub.2O.sub.X+5  [Chemical Formula 1] (where M.sub.1 denotes one selected from among manganese (Mn), cobalt (Co), and nickel (Ni), and X denotes a real number having a value between 1 and 3.)
(M.sub.2).sub.YVO.sub.4  [Chemical Formula 2] (where M.sub.2 denotes one selected from among lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu), and Y denotes a real number having a value between 0.5 and 1.5).

An ammonia oxidation catalyst device, including a substrate, a first catalyst coat layer and a second catalyst coat layer, wherein: the first catalyst coat layer includes inorganic oxide particles and a catalytic noble metal supported on the inorganic oxide particles; the second catalyst coat layer includes an NO.sub.x selective reduction catalyst and a proton zeolite H-Zeolite; the first catalyst coat layer is present on the substrate; and the second catalyst coat layer is present on the first catalyst coat layer.