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. %.

A method includes supplying a gas containing acrolein to a fixed bed reactor including a reaction tube to produce acrylic acid by vapor phase catalytic oxidation of acrolein. The reaction tube is packed with catalysts having different activities in such a way that catalyst layers are formed in a tube axis direction. A catalyst X having the highest activity among the catalysts contained in all the catalyst layers is placed in the whole or a part of a section up to 30% of a length of all the catalyst layers from a rearmost portion on a gas outlet side toward a gas inlet side. A catalytically active component x in the catalyst X has Mo, V, and optionally Cu. When Cu is included, its amount is 0.8 mol or less per 12 mol of Mo. A specific surface area of the catalytically active component x is 15-40 m.sup.2/g.

The present disclosure relates to a device for accurately measuring photocatalytic efficiency. Additional embodiments of the present disclosure further relate to a method of utilizing the disclosed device, for example, to obtain accurate measurements of photocatalytic efficiency and a photocatalyst compatible with the device in the present disclosure. Application of the present disclosure may include the quantification of photocatalytic light conversion metrics such as in a research environment.

The method for preparing a ferrite-based coating catalyst including mixing a support, a ferrite-based catalyst, a cellulose-based additive, and water, in which a content of the cellulose-based additive is 0.5 wt % or less based on a total weight of the ferrite-based catalyst.

A process for producing a catalytically active multielement oxide comprising the elements Mo, W, V and Cu, wherein at least one source of the elemental constituents W of the multielement oxide is used to produce an aqueous solution, the resultant aqueous solution is admixed with sources of the elemental constituents Mo and V of the multielement oxide, drying of the resultant aqueous solution produces a powder P, the resultant powder P is optionally used to produce geometric shaped precursor bodies, and the powder P is or the geometric shaped precursor bodies are subjected to thermal treatment to form the catalytically active composition, wherein the aqueous solution used for drying comprises from 1.6% to 5.0% by weight of W and from 7.2% to 26.0% by weight of Mo, based in each case on the total amount of aqueous solution.

Photoreduction of graphene oxide, by UV-generated ketyl radicals, to graphene. The photoreduction is versatile and can be carried out in solution, solid-state, and even in polymer composites. Reduction of graphene oxide can take place in various polymer matrixes. Methods for producing graphene-supported metal nanoparticles by photoreduction. Graphene oxide and a metal nanoparticle precursor are simultaneously reduced by the action of photogenerated ketyl radicals. Photoreduction is performed on polymer composite films in one embodiment.

The invention discloses a core-shell structured catalyst comprising a core covered with a shell. The core is made of hematite, tourmaline, germanium, maifanite or kaolin. The invention also provides a method for preparing the catalyst including mixing raw materials of the core with water to form seed-balls with a particle size of 2-4 mm; mixing the seed-balls with raw materials of the shell and water, such that the seed-balls are covered with the raw materials of the shell to form pellets with a particle size of 3-5 mm; processing the pellets at 60-90° C. and then calcining to active the pellets at 450-550° C. to obtain a core-shell structured catalyst. The invention further discloses use of the core-shell structured catalyst in the ozone oxidation reaction. In the invention, a core-shell structured catalyst with good morphology and catalytic performance is prepared, and the production cost of the catalyst is reduced.

Disclosed herein is a process and an apparatus for producing coated catalysts. A process of the present disclosure includes providing a composition containing a liquid and a catalytically active material and/or a precursor thereof in a stock vessel, providing a support material in a vessel which is rotatable about a longitudinal axis, transporting the composition from the stock vessel through a first conduit to a spray nozzle, transporting a propellant fluid through a second conduit to the spray nozzle, atomizing the composition and propellant fluid in the nozzle to produce an aerosol that flows into the vessel and impregnates the support material present therein, heating the vessel so the liquid present in the aerosol evaporates from the support material and the finely divided support material which has been treated with catalytically active material and/or a precursor thereof is dried, and discharging the vaporized liquid from the vessel.

The present disclosure relates to the technical field of industrial waste gas purification, in particular to a core-shell structured catalyst, a preparation method and use thereof. The present disclosure provides a core-shell structured catalyst including a metal oxide-molecular sieve as a core and porous silica (SiO.sub.2) as a shell, where the metal oxide-molecular sieve includes a molecular sieve and a metal oxide loaded on the molecular sieve, the metal oxide includes an oxide of a first metal and an oxide of a second metal, the first metal is Fe, Cu, Ti, Ni or Mn, and the second metal is Ce or La. The core-shell structured catalyst of the present disclosure can enable effective removal of HCN and AsH.sub.3 at the same time with a stable effect, and no secondary pollution.

The invention is directed to a catalyst, to a method for manufacturing a catalyst, to a method for manufacturing a bisphenol compound, and to the use of a catalyst. The catalyst of the invention comprises particles having a core and a shell, wherein the shell comprises an ion exchange resin covering the core at least in part and wherein the core has a density that is higher than the density of the ion exchange resin.