The present invention relates to a supported catalyst that can be used to produce a carbon nanotube aggregate with high bulk density, a method for preparing the supported catalyst, a carbon nanotube aggregate produced using the supported catalyst, and a method for producing the carbon nanotube aggregate. According to the present invention, the bulk density of the carbon nanotube aggregate is easily controllable. Therefore, the carbon nanotube aggregate is suitable for use in various fields.

A photocatalytic member comprises a base and a photocatalytic layer fixed on the base. The photocatalytic layer comprises first photocatalyst particles being visible light responsive photocatalyst particles for hydrogen generation, second photocatalyst particles being visible light responsive photocatalyst particles for oxygen generation, and conductive particles which are provided between the first photocatalyst particle and the second photocatalyst particle, have Fermi level at a negative position relative to an electronic energy level at the upper end of the valence band of the first photocatalyst particle and at a positive position relative to an electronic energy level at the bottom end of the conduction band of the second photocatalyst particle, and are able to store an electron and a hole. In the photocatalytic layer, the conductive particles are located to be coupled to both the first photocatalyst particles and the second photocatalyst particles.

An embodiment of the present invention provides a method for manufacturing multi-wall carbon nanotubes, the method comprising the steps of: (a) dissolving a metal precursor in a solvent to prepare a precursor solution; (b) perform thermal decomposition while spraying the precursor solution into a reactor, thereby forming a catalyst powder; and (c) introducing the catalyst powder into a fluidized-bed reactor heated to 600-900 C. and spraying a carbon-based gas and a carrier gas to synthesize multi-wall carbon nanotubes from the catalyst powder, wherein steps (a) to (c) are performed in a continuous type and wherein the catalyst powder contains metal components according to equation 1 below. <Equation 1> Ma:Mb=x:y, wherein 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.

Provide is a functional structural body that can suppress aggregation of metal oxide nanoparticles and prevent functional loss of metal oxide nanoparticles, and thus exhibit a stable function over a long period of time. A functional structural body (1) includes: a skeletal body (10) of a porous structure composed of a zeolite-type compound; and at least one type of metal oxide nanoparticles (20) containing a perovskite-type oxide present in the skeletal body (10), the skeletal body (10) having channels (11) that connect with each other, and the metal oxide nanoparticles (20) being present at least in the channels (11) of the skeletal body (10).

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.

Oxidative dehydrogenation is an alternative to the energy extensive steam cracking process presently used for the production of olefins from paraffins, but has not been implemented commercially partially due to the unstable nature of hydrocarbon/oxygen mixtures, and partially due to the cost involved in the construction of new facilities. An oxidative dehydrogenation chemical complex designed to reduce costs by including integration of an oxygen separation module that also addresses safety concerns and reduces emission of greenhouse gases is described.

An object of the present invention is to provide a catalyst ensuring that when a gas-phase catalytic oxidation reaction of a material substance is conducted using a catalyst to produce a target substance, the pressure loss and coking are suppressed and the target substance can be produced in high yield. The present invention is related to a ring-shaped catalyst having a straight body part and a hollow body part, which is used when a gas-phase catalytic oxidation reaction of a material substance is conducted to produce a target substance, wherein a length of the straight body part is shorter than a length of the hollow body part and at least at one end part, a region from an end part of the straight body part to an end part of the hollow body part is concavely curved.

An industrial furnace and a method for roasting or regenerating spent petroleum catalysts. The furnace particularly includes a device to set the catalysts in motion along the bottom of the furnace to cause the catalysts to circulate from the inlet towards the outlet of the furnace; a first zone decarbonizing the spent catalysts to obtain decarbonized catalysts, followed by: a second zone including a plurality of oxygen feed devices distributed along the length of the second zone and placing the decarbonized catalysts in contact with the oxygen feed, the second zone desulfurizing the decarbonized catalysts to obtain roasted or regenerated catalysts.

A hydroprocessing catalyst or catalyst precursor has been developed. The catalyst is a transition metal molybdotungstate material or metal sulfides derived therefrom. The hydroprocessing using the transition metal molybdotungstate material may include hydrodenitrification, hydrodesulfurization, hydrodemetallation, hydrodesilication, hydrodearomatization, hydroisomerization, hydrotreating, hydrofining, and hydrocracking.

A process for producing an eggshell catalyst, comprising the coating of the outer surface of a geometric shaped support body with a catalytically active multielement oxide or a powder P, wherein the powder P, after being coated, is converted by thermal treatment to a catalytically active multielement oxide, and one or more liquid binders, wherein the coating is conducted in a horizontal mixer and the Froude number during the coating in the horizontal mixer is from 0.0160 to 0.1200.