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.

The present invention relates to a process for producing mixed oxide catalysts on the basis of molybdenum and bismuth oxides in which the precursor compounds of the components of mixed oxide catalysts provided in the form of a solution and/or suspension are subjected to a spray-drying with a specific temperature regime and the spray particles obtained in this way are then calcined to yield a catalytic active mass, and to the mixed oxide catalysts obtainable by this process and to the use of these catalysts in the partial oxidation of olefins, in particular in the partial gas phase oxidation of propene to acrolein and acrylic acid. The spray drying of the precursor compounds containing solution or suspension is performed in concurrent with a gas stream having a specific entrance temperature. Alternatively, when the main gas stream has a higher entrance temperature, an additional colder gas stream can be fed in downstream. The thus obtained mixed oxide catalysts give lower a maximum temperature in the hot spot of catalyst fixed bed when they are used in the partial gas phase oxidation of olefins.

The present invention provides a monatomic metal-doped few-layer molybdenum disulfide electrocatalytic material, a preparing method thereof, and a method for electrocatalytic nitrogen fixation. The material has a few-layer ultra-thin and irregular flake-like microstructure with a length and a width of nanometer scale. A doping metal in the monatomic metal-doped few-layer molybdenum disulfide electrocatalytic material is dispersed in a form of single atoms. When the catalyst is used in electrochemical reduction of N.sub.2, a Faradic efficiency in selective reduction of N.sub.2 into NH.sub.4.sup.+ is 18% or above, and stability of the catalyst is better.

The present invention provides a method for efficiently producing 1-chloro-3,3,3-trifluoropropene from a low-reactivity intermediate product. More specifically, provided is a method for producing trans-1-chloro-3,3,3-trifluoropropene, characterized by reacting a halogenated C.sub.3 hydrocarbon compound represented by the following general formula (1) with hydrogen fluoride in a gas phase in the presence of a solid catalyst and chlorine
C.sub.3H.sub.XCl.sub.YF.sub.Z(1)
wherein X is 2 or 3; when X=2, Y is an integer of 1 to 4, Z is an integer of 0 to 3, and Y+Z=4; and, when X=3, Y is an integer of 1 to 5, Z is an integer of 0 to 4, and Y+Z=5; provided that the general formula (1) represents any halogenated C.sub.3 hydrocarbon compound other than trans-1-chloro-3,3,3-trifluoropropene.

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.

The present invention provides a method for efficiently producing 1-chloro-3,3,3-trifluoropropene from a low-reactivity intermediate product. More specifically, provided is a method for producing trans-1-chloro-3,3,3-trifluoropropene, characterized by reacting a halogenated C.sub.3 hydrocarbon compound represented by the following general formula (1) with hydrogen fluoride in a gas phase in the presence of a solid catalyst and chlorine

C.sub.3H.sub.XCl.sub.YF.sub.Z (1)

wherein X is 2 or 3; when X=2, Y is an integer of 1 to 4, Z is an integer of 0 to 3, and Y+Z=4; and, when X=3, Y is an integer of 1 to 5, Z is an integer of 0 to 4, and Y+Z=5; provided that the general formula (1) represents any halogenated C.sub.3 hydrocarbon compound other than trans-1-chloro-3,3,3-trifluoropropene.

The present invention provides a monatomic metal-doped few-layer molybdenum disulfide electrocatalytic material, a preparing method thereof, and a method for electrocatalytic nitrogen fixation. The material has a few-layer ultra-thin and irregular flake-like microstructure with a length and a width of nanometer scale. A doping metal in the monatomic metal-doped few-layer molybdenum disulfide electrocatalytic material is dispersed in a form of single atoms. When the catalyst is used in electrochemical reduction of N.sub.2, a Faradic efficiency in selective reduction of N.sub.2 into NH.sub.4.sup.+ is 18% or above, and stability of the catalyst is better.

The present invention relates to a process for producing mixed oxide catalysts on the basis of molybdenum and bismuth oxides in which the precursor compounds of the components of mixed oxide catalysts provided in the form of a solution and/or suspension are subjected to a spray-drying with a specific temperature regime and the spray particles obtained in this way are then calcined to yield a catalytic active mass, and to the mixed oxide catalysts obtainable by this process and to the use of these catalysts in the partial oxidation of olefms, in particular in the partial gas phase oxidation of propene to acrolein and acrylic acid. The spray drying of the precursor compounds containing solution or suspension is performed in concurrent with a gas stream having a specific entrance temperature. Alternatively, when the main gas stream has a higher entrance temperature, an additional colder gas stream can be fed in downstream. The thus obtained mixed oxide catalysts give lower a maximum temperature in the hot spot of catalyst fixed bed when they are used in the partial gas phase oxidation of olefms.