In a method for producing hydrogen and carboxylic acid, a primary alcohol of 1 to 7 carbon atoms and water are reacted by being continuously introduced into a flow reactor packed with a solid catalyst consisting of an alloy of ruthenium and tin on a support and passed through the reactor under temperature and pressure conditions at which the water assumes a gaseous state. This method enables hydrogen and carboxylic acid to be produced in a high yield or at a high purity from a primary alcohol and water in a short time and by simple operations.

Provided are titanium oxide particles having a higher photocatalytic activity, particularly a higher visible light activity as compared to the conventional ones; a dispersion liquid thereof; a photocatalyst thin film formed using such dispersion liquid; a member having such photocatalyst thin film on its surface; and a method for producing the titanium oxide particle dispersion liquid. The titanium oxide particles are those with (1) a tin component and a visible light activity-enhancing transition metal component being solid-dissolved in the particles; and with (2) an iron component, a titanium component and a silicon component being adhered to the surfaces of the particles. The titanium oxide particle dispersion liquid is one with the titanium oxide particles being dispersed in an aqueous dispersion medium.

Provided are titanium oxide particles having a higher photocatalytic activity as compared to the conventional ones; a dispersion liquid thereof; a photocatalyst thin film formed using such dispersion liquid; a member having such photocatalyst thin film on its surface; and a method for producing the titanium oxide particle dispersion liquid. The titanium oxide particles are those with a titanium component and a silicon component being adhered to the surfaces thereof, wherein a molar ratio of the titanium component to titanium oxide (TiO.sub.2/Ti) is 10 to 10,000, and a molar ratio of the silicon component to titanium oxide (TiO.sub.2/Si) is 1 to 10,000; and the titanium oxide particle dispersion liquid is one with such titanium oxide particles being dispersed in an aqueous dispersion medium.

A system suitable for oxidizing ammonia with oxygen in the presence of catalysts is described. The system includes a reactor equipped with at least one supply line for a reactant gas mixture and at least one discharge line for a process gas; a catalyst comprising at least one transition metal oxide that is not an oxide of a platinum metal; and a device for adjusting a molar ratio of oxygen to ammonia of less than or equal to 1.75 mol/mol in the reactant gas mixture by mixing an oxygen-containing gas stream having an O.sub.2 content of <20% by volume with a chosen amount of ammonia. The oxygen-containing gas stream is produced by a device for: diluting an air stream with a gas stream comprising less than 20% by volume oxygen; or depleting oxygen from an oxygen-containing gas mixture, preferably from air; or by a combination thereof.

Disclosed is a method of preparing a high-performance zeolite catalyst for reducing nitrogen oxide emissions, and more particularly a technique for preparing a zeolite catalyst, suitable for use in effectively removing nitrogen oxide (NOx), among exhaust gases emitted from vehicle internal combustion engines through selective catalytic reduction (SCR), thereby exhibiting high efficiency, high chemical stability and high thermal durability upon SCR using the prepared catalyst.

A process of preparing a solid catalyst component for the production of polypropylene includes a) dissolving a halide-containing magnesium compound in a mixture, the mixture including an epoxy compound, an organic phosphorus compound, and a hydrocarbon solvent to form a homogenous solution; b) treating the homogenous solution with an organosilicon compound during or after the dissolving step; c) treating the homogenous solution with a first titanium compound in the presence of a first non-phthalate electron donor, and an organosilicon compound, to form a solid precipitate; and d) treating the solid precipitate with a second titanium compound in the presence of a second non-phthalate electron donor to form the solid catalyst component, where the process is free of carboxylic acids and anhydrides.

Disclosed are a high-entropy nitride ceramic fiber, and a preparation method and use thereof. The high-entropy ceramic fiber comprises Ti, Hf, Ta, Nb, and Mo; the high-entropy nitride ceramic fiber presents single crystal phase, and each of the elements are uniformly distributed at molecular level. The preparation method of the high-entropy ceramic fiber comprises: mixing a high-entropy ceramic precursor comprising the target metal elements, a spinning aid, and a solvent uniformly to prepare a precursor spinning solution, followed by working procedures of spinning, pyrolyzation, and nitriding to prepare the high-entropy nitride ceramic fiber. The high-entropy nitride ceramic fiber can be used in photocatalysis process of carbon dioxide to prepare methane.

The present disclosure is generally directed to polyolefin polymers, such as polypropylene homopolymers, and propylene-ethylene copolymers that have improved flow properties. In one embodiment, the polymers can be produced using a solid catalyst component that includes a) dissolving a halide-containing magnesium compound in a mixture, the mixture including an epoxy compound, an organic phosphorus compound, and a hydrocarbon solvent to form a homogenous solution; b) treating the homogenous solution with an organosilicon compound during or after the dissolving step; c) treating the homogenous solution with a first titanium compound in the presence of a first non-phthalate electron donor, and an organosilicon compound, to form a solid precipitate; and d) treating the solid precipitate with a second titanium compound in the presence of a second non-phthalate electron donor to form the solid catalyst component, where the process is free of carboxylic acids and anhydrides.

A catalyst includes at least one element X selected from the group consisting of Groups 3 to 6 of the Periodic Table, and at least one element Z selected from the group consisting of Group 14 elements. At least one diffraction peak is observed in a low angle range of θ=6° or less in an X-ray diffraction profile observed using X-ray diffraction. The at least one diffraction peak has a ratio (I/H) of a peak intensity I to a half width at half maximum H of the diffraction peak of 5000 or more.

An exemplary embodiment of the present application provides a method for preparing butadiene, the method comprising a process of performing an oxidative dehydrogenation reaction by introducing a reactant comprising butene, oxygen, nitrogen, and steam into a reactor which is filled with a catalyst, in which during a first start-up of the oxidative dehydrogenation reaction, the oxygen is introduced into the reactor before the butene, or the oxygen is introduced into the reactor simultaneously with the butene.