Provided is a catalyst for manufacturing multi-wall carbon nanotubes, the catalyst including metal components according to <Equation> Ma:Mb=x:y, and having a hollow structure with a thickness of 0.5-10 m. In the above equation, Ma represents at least two metals selected from Fe, Ni, Co, Mn, Cr, Mo, V, W, Sn, and Cu; Mb represents at least one metal selected from Mg, Al, Si, and Zr; x and y each represent the molar ratio of Ma and Mb; and x+y=10, 2.0x7.5, and 2.5y8.0.

The present disclosure relates to an FCC catalyst additive for cracking of petroleum feedstock and a process for its preparation. The FCC catalyst additive of the present disclosure comprises at least one zeolite, at least one clay, at least one binder, phosphorous in the form of P.sub.2O.sub.5, and at least one Group IVB metal compound. The FCC catalyst additive of the present disclosure is hydrothermally stable and has improved matrix surface area even after various hydrothermal treatments. The FCC catalyst additive of the present disclosure can be used in combination with the conventional FCC catalyst for catalytic cracking to selectively enhance the propylene and LPG yields.

The present invention relates to an impregnated supported catalyst, a carbon nanotube aggregate, and a method for producing the carbon nanotube aggregate. The carbon nanotube aggregate includes a four-component catalyst in which catalytic components and active components are supported on a granular support, and bundle type carbon nanotubes grown on the catalyst. The carbon nanotube aggregate has an average particle diameter of 100 to 800 m, a bulk density of 80 to 250 kg/m.sup.3, and a spherical or potato-like shape.

This invention relates to a composite composition for harmful gas removal containing a copper-manganese catalyst, which is capable of removing ambient and indoor pollutants, such as carbon monoxide and volatile organic compounds, the composite composition including a copper-manganese composite catalyst hybridized with an inorganic layer compound, an inorganic filler, activated carbon, and a binder.

Ceramic compositions with catalytic activity are provided, along with methods for using such catalytic ceramic compositions. The ceramic compositions correspond to compositions that can acquire increased catalytic activity by cyclic exposure of the ceramic composition to reducing and oxidizing environments at a sufficiently elevated temperature. The ceramic compositions can be beneficial for use as catalysts in reaction environments involving swings of temperature and/or pressure conditions, such as a reverse flow reaction environment. Based on cyclic exposure to oxidizing and reducing conditions, the surface of the ceramic composition can be converted from a substantially fully oxidized state to various states including at least some dopant metal particles supported on a structural oxide surface.

Catalysts and catalytic methods are provided. The catalysts and methods are useful in a variety of catalytic reactions, for example, the oxidative coupling of methane.

A process for activating a fixed catalyst bed is disclosed. The fixed catalyst bed includes monolithic shaped catalyst bodies or include monolithic shaped catalyst bodies including at a first metal selected from Ni, Fe, Co, Cu, Cr, Pt, Ag, Au and Pd, and a second component selected from Al, Zn and Si. The fixed catalyst bed, for activation, is treated with an aqueous base having a strength of not more than 3.5% by weight. The base is selected from alkali metal hydroxides, alkaline earth metal hydroxides and mixtures thereof. The fixed catalyst bed has a temperature gradient during the activation and the temperature differential between the coldest point in the fixed catalyst bed and the warmest point in the fixed catalyst bed is kept at not more than 50 K.

Described herein is a process for providing a catalytically active fixed bed for hydrogenation of organic compounds, in which a fixed bed including monolithic shaped bodies as catalyst supports or consisting of monolithic shaped bodies is introduced into a reactor and the fixed bed is then contacted with at least one catalyst or a precursor thereof. The fixed beds laden with a catalyst that are obtained in this way are especially suitable for the hydrogenation of organic compounds in the presence of CO, wherein the conversion is at least 90%. They are notable in that only a very small proportion, if any, of the catalyst introduced is released into the reaction medium.

The invention relates to a silver-comprising catalyst system for the preparation of aldehydes and/or ketones by oxidative dehydrogenation of alcohols, in particular the oxidative dehydrogenation of methanol to form formaldehyde, comprising a first catalyst layer and a second catalyst layer, wherein the first catalyst layer consists of a silver-comprising material in the form of balls of wire, gauzes or knitteds having a weight per unit area of from 0.3 to 10 kg/m.sup.2 and a wire diameter of from 30 to 200 m and the second catalyst layer consists of a silver-comprising material in the form of granular material having an average particle size of from 0.5 to 5 mm and the two catalyst layers are in direct contact with one another. The invention further relates to a corresponding process for the preparation of aldehydes and/or ketones, in particular of formaldehyde, by oxidative dehydrogenation of corresponding alcohols over a silver-comprising catalyst system.

A manufacturing method for supported catalysts comprising a step A of forming a mixed layer having a catalyst component and a catalyst carrier component on at least a portion of the surface of a support body having a catalytic layer by bringing a mixed solution comprising a catalyst raw material and a catalyst carrier raw material into contact with the support body having a catalytic layer on the surface. Furthermore, such a manufacturing method for supported catalysts preferably comprises a step B in which the catalyst component is made to segregate to a surface of the mixed layer after step A.