The present invention relates to an eco-friendly method for preparing a porous silicon carbide structure, which is capable of preparing a porous silicon carbide structure having meso- or macro-sized pores without using a harmful phenolic resin as a carbon source.

The present invention relates to SiC nanostructures, including SiC nanopowder, SiC nanowires, and composites of SiC nanopowder and nanowires, which can be used as catalyst supports in membrane electrode assemblies and in fuel cells. The present invention also relates to composite catalyst supports comprising nanopowder and one or more inorganic nanowires for a membrane electrode assembly.

A process of methane catalytic conversion produces olefins, aromatics, and hydrogen under oxygen-free, continuous flowing conditions. Such a process has little coke deposition and realizes atom-economic conversion. Under the conditions encountered in a fixed bed reactor (i.e. reaction temperature: 750-1200 C.; reaction pressure: atmospheric pressure; the weight hourly space velocity of feed gas: 1000-30000 ml/g/h; and fixed bed), conversion of methane is 8-50%. The selectivity of olefins is 30-90%. And selectivity of aromatics is 10-70%. The catalyst for this methane conversion has a SiO.sub.2-based matrix having active species that are formed by confining dopant metal atoms in the lattice of the matrix.

A process of methane catalytic conversion produces olefins, aromatics, and hydrogen under oxygen-free, continuous flowing conditions. Such a process has little coke deposition and realizes atom-economic conversion. Under the conditions encountered in a fixed bed reactor (i.e. reaction temperature: 750-1200 C.; reaction pressure: atmospheric pressure; the weight hourly space velocity of feed gas: 1000-30000 ml/g/h; and fixed bed), conversion of methane is 8-50%. The selectivity of olefins is 30-90%. And selectivity of aromatics is 10-70%. The catalyst for this methane conversion has a SiO.sub.2-based matrix having active species that are formed by confining dopant metal atoms in the lattice of the matrix.

A plugged honeycomb structure includes a honeycomb structure body, and a plurality of plugging portions, the honeycomb structure body further includes pass-through hole portions each of which is formed in at least a part of a partition wall intersection portion in which the partition walls intersect in one end face and each of which interconnects a pair of cells facing each other at a position corresponding to the partition wall intersection portion to enable pass-through of a fluid, and a value obtained by dividing a diameter of a first virtual inscribed circle inscribed at a position of a minimum hole width of the pass-through hole portion by a diameter of a second virtual inscribed circle inscribed at a position of a minimum plugging width between the plugging portions facing each other is in a range of 0.05 to 0.74.

A plugged honeycomb structure includes a honeycomb structure body, and a plurality of plugging portions, the honeycomb structure body further includes pass-through hole portions each of which is formed in at least a part of a partition wall intersection portion in which the partition walls intersect in one end face and each of which interconnects a pair of cells facing each other at a position corresponding to the partition wall intersection portion to enable pass-through of a fluid, and a value obtained by dividing a diameter of a first virtual inscribed circle inscribed at a position of a minimum hole width of the pass-through hole portion by a diameter of a second virtual inscribed circle inscribed at a position of a minimum plugging width between the plugging portions facing each other is in a range of 0.05 to 0.74.

The present disclosure provides a process for producing trifluoroiodomethane (CF.sub.3I). The process may include providing a vapor-phase reactant stream comprising trifluoroacetic acid and iodine and reacting the reactant stream in the presence of a catalyst to produce a product stream comprising the trifluoroiodomethane. The catalyst includes silicon carbide.

The present invention relates to a method for preparing a metal catalyst (Ni, Co, etc.)-supported porous silicon carbide structure having meso- to macro-sized pores, high porosity and superior mechanical properties. Unlike the existing method wherein a porous silicon carbide structure is prepared and then the metal catalyst is infiltrated therein, the preparation of the porous silicon carbide structure and the supporting of the metal catalyst occur at the same time by the mixing metal catalyst material and starting materials. As a result, the metal catalyst is distributed uniformly in the porous silicon carbide structure and it is possible to locate a desired amount of the metal catalyst inside the porous silicon carbide structure.

The present invention relates to a method for preparing a metal catalyst (Ni, Co, etc.)-supported porous silicon carbide structure having meso- to macro-sized pores, high porosity and superior mechanical properties. Unlike the existing method wherein a porous silicon carbide structure is prepared and then the metal catalyst is infiltrated therein, the preparation of the porous silicon carbide structure and the supporting of the metal catalyst occur at the same time by the mixing metal catalyst material and starting materials. As a result, the metal catalyst is distributed uniformly in the porous silicon carbide structure and it is possible to locate a desired amount of the metal catalyst inside the porous silicon carbide structure.

Some embodiments are directed to a new methodology aimed at preparing highly N-doped mesoporous carbon macroscopic composites, and their use as highly efficient heterogeneous metal-free catalysts in a number of industrially relevant catalytic transformations.