The present invention relates to a catalyst system for oxidation of o-xylene and/or naphthalene to phthalic anhydride (PA) comprising at least four catalyst zones arranged in succession in the reaction tube and filled with catalysts of different chemical composition wherein the active material of the catalysts comprise vanadium and titanium dioxide and the active material of the catalyst in the last catalyst zone towards the reactor outlet has an antimony content (calculated as antimony trioxide) between 0.7 to 3.0 wt. %. The present invention further relates to a process for gas phase oxidation in which a gas stream comprising at least one hydrocarbon and molecular oxygen is passed through a catalyst system which comprises at least four catalyst zones arranged in succession in the reaction tube and filled with catalysts of different chemical composition wherein the active materials of the catalysts comprise vanadium and titanium dioxide and the active material of the catalyst in the last catalyst zone towards the reactor outlet has an antimony content (calculated as antimony trioxide) between 0.7 to 3.0 wt. %.

Described are catalytic articles comprising a substrate having a washcoat on the substrate, the washcoat containing a catalytic component having a first average (D50) particle size and a functional binder component having a second average (D50) particle size in the range of about 10 nm to about 1000 nm, wherein the ratio of the first average (D50) particle size to the second average (D50) particle size is greater than about 10:1. The catalytic articles are useful in methods and systems to purify exhaust gas streams from an engine.

An object of the present invention is to provide ferrite particles for supporting a catalyst having a small apparent density, various properties are maintained in a controllable state and a specified volume is filled with a small weight, and a catalyst using the ferrite particles for supporting a catalyst. To achieve the object, ferrite particles for supporting a catalyst provided with an outer shell structure containing Ti oxide, a catalyst using the ferrite particles for supporting a catalyst are employed.

The invention relates to a catalyst which comprises: a) a mixed metal oxide of molybdenum, vanadium, niobium and optionally tellurium; and b) ceria particles having a crystallite size greater than 15 nanometers (nm); wherein the amount of the ceria particles, based on the total amount of the catalyst, is of from 1 to 60 wt. %. Further, the invention relates to a process for preparing a catalyst, which comprises mixing a mixed metal oxide of molybdenum, vanadium, niobium and optionally tellurium with ceria particles having a crystallite size greater than 15 nanometers (nm), wherein the amount of the ceria particles, based on the total amount of the catalyst, is of from 1 to 60 wt. %. Still further, the invention relates to an alkane oxidative dehydrogenation and/or alkene oxidation process wherein such catalyst is used.

An efficient photocatalyst nanocomposite comprising reduced graphene oxide, noble metal, and a metal oxide prepared by a one-step method that utilizes date seed extract as a reducing and nanoparticle determining size agent. The photocatalyst of the invention is a more effective sunlight photocatalyst than that prepared by traditional method in the photo decomposition of organic compounds in contaminated water.

An apparatus for forming methane from carbon dioxide and hydrogen is described. The apparatus comprises: a dielectric barrier discharge, DBD, device arranged to generate a plasma; and a passageway having an inlet for the carbon dioxide and the hydrogen and an outlet for the methane and including therein a catalyst comprising nickel and alumina. The passageway extends, at least in part, through the DBD device wherein, in use, the carbon dioxide is exposed to the catalyst in the presence of the hydrogen in the generated plasma, thereby forming the methane from at least some of the carbon dioxide and the hydrogen. A method, a use and a catalyst are also described.

The present invention relates to a filter medium (10) for air and/or water cleaning, comprising a semiconductor photocatalytic material (14) and a light energy source (15) for radiating light provided to activate photocatalytic reactions of the semiconductor photocatalytic material (14). The light energy source (15) is configured as a support (16) for the semiconductor photocatalytic material (14). The filter medium (10) can be incorporated into a filter unit (100).

Disclosed are a spherelike supermacroporous mesoporous material, a polyolefin catalyst, and a preparation method therefor and an olefin polymerization process. The spherelike supermacroporous mesoporous material has a twodimensional hexagonal ordered pore channel structures. The mesoporous material has an average pore size of 10 nm to 15 nm, a specific surface area of 300 m.sup.2/g to 400 m.sup.2/g, and an average particle size of 1 .Math.m to 3 .Math.m, based on the total mass of the mesoporous material. The mass content of water in the mesoporous material is < 1 ppm. The mass content of oxygen in the mesoporous material is < 1 ppm. When a polyolefin catalyst prepared with the mesoporous material as a carrier is used for an olefin polymerization reaction, the a polyolefin product with a narrow molecular weight distribution and a good melt index can be obtained.

Provided are a superatomic material, as well as a sol, a preparation method therefor, and application thereof. The superatomic material comprises a carrier and superatoms doped in the carrier, the superatoms being one or more of silver, copper, zinc superatoms and rare earth element superatoms, the scale of superatoms being 100-3000 pm, and the carrier being an inorganic carrier. The superatomic material and the sol have superior antimicrobial and antiviral properties, have a long service life, and are environmentally friendly.

An oxidation catalyst composition is provided, the composition including a plurality of platinum group metal particles having a multi-modal distribution of particle sizes. The plurality of platinum group metal particles includes a first population of platinum group metal particles having a range of particle sizes of from about 0.5 nm to about 3 nm, and a second population of platinum group metal particles having a range of particle sizes of from about 4 nm to about 15 nm. Methods for the preparation and use of the catalyst composition are also provided, as well as catalyst articles and emission gas treatment systems employing such catalyst articles. The catalyst exhibits enhanced stability with respect to oxidation performance after degreening and/or aging, as compared to conventional oxidation catalysts, in particular less loss of NOx oxidation performance.