The present invention relates to a supported catalyst having a structure in which a metal catalyst is supported on a core-shell structured support. The support includes core particles and shell particles having a smaller particle diameter than the core particles and coated on the core particles to form a shell layer. Due to this structure, the supported catalyst can be used to produce carbon nanostructures that form a novel secondary structure in which ends of the carbon nanostructures are supported on the supported catalyst and form independent branches and the opposite ends grow and are assembled together. The novel structure is expected to find application in various fields, such as energy materials, functional composites, pharmaceuticals, batteries, and semiconductors, because of its characteristic shape.

An artificial photosynthesis module includes an oxygen generation electrode having a first photocatalyst layer that decomposes water with light to generate oxygen, and has a first substrate, a first conductive layer, a first photocatalyst layer, and a first co-catalyst, and a hydrogen generation electrode that decomposes water with light to generate hydrogen and has a second substrate, a second conductive layer, a second photocatalyst layer, and a second co-catalyst. This provides an artificial photosynthesis module with high reaction efficiency.

An artificial photosynthesis module includes an oxygen generation electrode having a first photocatalyst layer that decomposes water with light to generate oxygen, and has a first substrate, a first conductive layer, a first photocatalyst layer, and a first co-catalyst, and a hydrogen generation electrode that decomposes water with light to generate hydrogen and has a second substrate, a second conductive layer, a second photocatalyst layer, and a second co-catalyst. This provides an artificial photosynthesis module with high reaction efficiency.

The present invention relates to entangled-type carbon nanotubes which have a bulk density of 31 kg/m.sup.3 to 85 kg/m.sup.3 and a ratio of tapped bulk density to bulk density of 1.37 to 2.05, and a method for preparing the entangled-type carbon nanotubes.

The present invention relates (i) to a method for producing a doped copper-tetraammine-salt-based hydrogenation catalyst suitable for the hydrogenation of an aromatic nitro compound such that an aromatic amine is obtained, the hydrogenation catalyst comprising copper in metal form or in oxidic form and a doping metal selected from iron, cobalt, manganese, vanadium, zinc or a mixture of two or more thereof in metal form or in oxidic form on a carrier, the carrier comprising silicon dioxide shaped bodies and/or silicon carbide shaped bodies, (ii) to a doped copper-tetraammine-salt-based hydrogenation catalyst obtainable using the aforementioned method according to the invention, and (iii) to a method for producing an aromatic amine, comprising the hydrogenation of an aromatic nitro compound in the presence of a doped copper-tetraammine-salt-based hydrogenation catalyst comprising copper in metal form or in oxidic form and comprising a doping metal in metal form or in oxidic form on a carrier as hydrogenation catalyst, the carrier comprising silicon dioxide shaped bodies and/or silicon carbide shaped bodies, and the hydrogenation catalyst being, more particularly, the aforementioned hydrogenation catalyst according to the invention.

The present invention relates to a method for preparing a catalyst which can produce carbon nanotubes having a higher bulk density by supporting a catalyst component under pressurized conditions, and to a method for producing carbon nanotubes using the catalyst so produced.

Oxidative dehydrogenation of paraffins to olefins provides a lower energy route to produce olefins. Oxidative dehydrogenation processes may be integrated with a number of processes in a chemical plant such as polymerization processes, manufacture of glycols, and carboxylic acids and esters. Additionally, oxidative dehydrogenation processes can be integrated with the back end separation process of a conventional steam cracker to increase capacity at reduced cost.

A denitrification catalyst using ceramic nanotubes grown on a porous metal structure, including: a porous metal structure having a plurality of pores formed between metal supports such that exhaust gas penetrates through the pores in multiple directions; ceramic nanotubes grown on the porous metal structure through anodic oxidation; and an active material uniformly and highly dispersed as a nano-thin film layer on inner and outer surfaces of the ceramic nanotubes through a deposition or supporting process.

A denitrification catalyst using ceramic nanotubes grown on a porous metal structure, including: a porous metal structure having a plurality of pores formed between metal supports such that exhaust gas penetrates through the pores in multiple directions; ceramic nanotubes grown on the porous metal structure through anodic oxidation; and an active material uniformly and highly dispersed as a nano-thin film layer on inner and outer surfaces of the ceramic nanotubes through a deposition or supporting process.

Use of a ternary vanadate of formula (I): Fe.sub.x MeI.sub.y MeII.sub.z VO.sub.4 wherein MeI and MeII are different from each other and each stand for an element selected from the group consisting of Y, La, Ce, Pr, Nd, Sm, Er, Gd, Tb, Dy, Ho, Tm, Yb, Lu, Al, Bi and Sb and wherein x=0.05-0.9; y=0.05-0.9; z=0.05-0.9; x+y+z=1, as a catalyst for the oxidation of carbonaceous compounds in combustion engines.