A catalyst may include a base material, a precious metal, and a metal oxide. At least a portion of the precious metal may form catalytically active sites on a surface of the metal oxide. The catalytically active sites may be formed by depositing the precious metal on the base material to form a catalyst structure, performing a first calcination on the catalyst structure, depositing the metal oxide on the catalyst structure, wherein the precious metal is at least partially encapsulated by the metal oxide, performing a second calcination on the catalyst structure, and reducing the catalyst structure with a reductive material, where at least a portion of the precious metal diffuses to a surface of the metal oxide to form the catalytically active sites.

Provided is a catalyst for an oxidative dehydrogenation reaction that comprises: a porous support; a core portion supported on the porous support and containing a first zinc ferrite-based catalyst; and a shell portion supported on the core portion and containing a second zinc ferrite-based catalyst, in which the first zinc ferrite-based catalyst and the second zinc ferrite-based catalyst are different from each other.

A three-way catalyst article with improved ammonia emission control, and its use in an exhaust system for gasoline engines, is disclosed. The catalyst article for treating exhaust gas from a gasoline engine comprising: a substrate comprising an inlet end, an outlet end with an axial length L; a first catalytic region beginning at the inlet end, wherein the first catalytic region comprises a first zeolite; and a second catalytic region beginning at the outlet end, wherein the second catalytic region comprises a second platinum group metal (PGM) component, a second oxygen storage capacity (OSC) material, and a second inorganic oxide; wherein the second PGM component is selected from the group consisting of palladium, platinum, rhodium and a combination thereof.

A high-adsorption-performance nanofiber filter medium includes a support material and a composite nanofiber filtration layer that includes multiple nanometer composite nanofiber layers deposited and stacked on the support material. The nanometer composite nanofiber layer includes first, second, and third nano-powder composite nanofibers, which are uniformly mixed by means of an airflow or are sequentially laminated to form the nanometer composite nanofiber layer. The nanometer composite nanofiber layer formed through sequential lamination includes first, second, and third nanofiber layers. The first nanofiber layer includes multiple first nano-powder composite nanofibers. The second nanofiber layer is stacked on the first nanofiber layer and includes multiple second nano-powder composite nanofibers. The third nanofiber layer is stacked on the second nanofiber layer and includes multiple third nano-powder composite nanofibers. The composite nanofiber filtration layer is formed of multiple nanometer composite nanofiber layers, so that the high-adsorption-performance nanofiber air filter medium shows improved performance.

The present disclosure relates to a multi-sandwich composite catalyst and a preparation method and application thereof. The present disclosure provides a preparation method of a multi-sandwich composite catalyst, comprises the following steps: sequentially depositing a first layer oxide, a first active metal, an oxide interlayer, a second active metal and a surface oxide on a template, and sequentially performing calcination and reduction, thereby obtaining a multi-sandwich composite catalyst; wherein the first active metal and the second active metal are different kinds of active metals. In the present disclosure, a multi-sandwich structure is formed by depositing the oxides and active metals alternately, so that the position and spacing distance of the active centers can be precisely controlled. The multi-sandwich composite catalyst prepared by the method provided described herein has a higher conversion than that of a catalyst without an interlayer when used for the catalytic reaction.

A three-way catalyst article, and its use in an exhaust system for internal combustion engines, is disclosed. The catalyst article for treating exhaust gas comprising: a substrate; and a first catalytic region on the substrate; wherein the first catalytic region comprises a first platinum group metal (PGM) component, wherein the first PGM component comprises PGM nanoparticles, wherein the PGM nanoparticles have an average particle size of about 1 to about 20 nm with a standard deviation (SD) no more than 1 nm.

The present invention relates to a catalyst comprising two layers on an inert catalyst carrier, wherein a layer A lying directly on the catalyst carrier contains at least one platinum group metal and one cerium/zirconium/SE mixed oxide, and a layer B, applied on layer A and in direct contact with the flow of exhaust gas, contains at least one platinum group metal and a cerium/zirconium/SE mixed oxide, wherein SE stands for a rare earth metal other than from cerium, characterized in that the fraction of SE oxide in the cerium/zirconium/SE mixed oxide of layer A is less than the fraction of SE oxide in the cerium/zirconium/SE mixed oxide of layer B.

A zeolite membrane structure includes a porous support, and a zeolite membrane. The zeolite membrane has a first zeolite layer located in a surface of the porous support, and a second zeolite layer located outside of the surface of the porous support and integrally formed with the first zeolite layer. The porous support has an outermost layer in which the first zeolite layer is located. An average thickness of the first zeolite layer is less than or equal to 5.4 micrometers. An average pore diameter of the outermost layer is greater than or equal to 0.050 micrometers and less than or equal to 0.150 micrometers.

Provided herein is an alkane dehydrogenation catalyst, a method of manufacturing an alkane dehydrogenation catalyst, and a method of converting alkanes to alkenes.

Provided is a method of preparing photoluminescent photocatalyst beads for removing harmful substances or viruses present in air, soil, and water, and more particularly to a method of preparing photoluminescent photocatalyst beads that are efficient in decomposing and removing a mixture of hard-to-decompose organic contaminants and removing viruses by preparing a photoluminescent photocatalyst in the form of a bead, and photoluminescent photocatalyst beads obtained from the method.