When the amount of coating is increased in a two-layer catalyst or the like containing two noble metals in respective different layers, gas diffusivity in the catalyst and use efficiency of a catalytic active site are reduced to thereby reduce purification performance. In view of this, an organic fiber having a predetermined shape is used as a pore-forming material in formation of an uppermost catalyst coating layer of a multi-layer catalyst, to thereby form an uppermost catalyst coating layer having a high-aspect-ratio pore excellent in connectivity and therefore excellent gas diffusivity.

The present invention provides a coating composition suitable for use in forming a coating that can reduce a concentration of pollutant gases in the environment. The coating composition includes from 0.01 to 10 vol.-% of mesoporous titania particles, relative to a total volume of the coating composition, and from 5 to 99.99 vol.-% of a polymeric material, relative to the total volume of the coating composition. The mesoporous titania particles have a continuous exterior convex surface, a particle diameter of ?1 ?m but ? to 50 ?m, a BET specific surface area of from 30 to 350 m.sup.2/g, a modal pore diameter of ?5 nm but ?50 nm, and a pore size distribution so that 85% or more of a total pore volume is associated with pores having a diameter of 10 ?m or less.

According to one or more embodiments disclosed herein, a mesoporous zeolite may be made by a method comprising contacting an initial zeolite material with ammonium hexafluorosilicate to modify the framework of the initial zeolite material, and forming mesopores in the framework-modified zeolite material. The contacting may form a framework-modified zeolite material. The mesoporous zeolites may be incorporated into catalysts.

Disclosed is a supported catalyst for the preparation of vinyl acetate monomer (VAM), a process for preparing a catalyst comprising an extruded alumina support, and a catalytic process for the manufacturing vinyl acetate using the supported catalyst. Specifically, it is shown that for activated palladium-gold VAM catalysts prepared using extruded alumina supports, enhanced performance is demonstrated with increased pore volume of the support, and the gas hourly space velocity (GHSV, hr.sup.1), which was found to significantly increase the space time yield as GHSV increased as compared to the non-extruded alumina supported catalysts.

A hydroconversion catalyst obtained by the process described, comprising a mesoporized zeolite with healed zeolitic structure, containing at least one network of micropores and at least one network of mesopores, having an atomic Si/Al ratio within the zeolite framework of greater than or equal to 2.3 and showing reduced amount of extra-framework aluminium with regard to that of a mesoporized zeolite with no healed zeolitic structure.

The present invention relates to a catalyst comprising a macroporous noble metal-containing zeolite material and a porous SiO.sub.2-containing binder, wherein the catalyst has a proportion of micropores of more than 70%, based on the total pore volume of the catalyst. The invention is additionally directed to a process for preparing the catalyst and to the use of the catalyst as an oxidation catalyst.

The present invention describes an improved process for the commercial scale production of high-quality catalyst materials. These improved processes allow for production of catalysts that have very consistent batch to batch property and performance variations. In addition these improved processes allow for minimal production losses (by dramatically reducing the production of fines or small materials as part of the production process). The improved process involves multiple steps and uses calcining ovens that allow for precisely control temperature increases where the catalyst is homogenously heated. The calcining gas is released into a separate heating chamber, which contains the recirculation fan and the heat source. Catalysts that may be produced using this improved process include but are not limited to catalysts that promote CO hydrogenation, reforming catalysts, Fischer Tropsch Catalysts, Greyrock GreyCat? catalysts, catalysts that homologate methanol, catalysts that promote hydrogenation of carbon compounds, and other catalysts used in industry.

The present invention describes an improved process for the commercial scale production of high-quality catalyst materials. These improved processes allow for production of catalysts that have very consistent batch to batch property and performance variations. In addition these improved processes allow for minimal production losses (by dramatically reducing the production of fines or small materials as part of the production process). The improved process involves multiple steps and uses calcining ovens that allow for precisely control temperature increases where the catalyst is homogenously heated. The calcining gas is released into a separate heating chamber, which contains the recirculation fan and the heat source. Catalysts that may be produced using this improved process include but are not limited to catalysts that promote CO hydrogenation, reforming catalysts, Fischer Tropsch Catalysts, Greyrock GreyCat? catalysts, catalysts that homologate methanol, catalysts that promote hydrogenation of carbon compounds, and other catalysts used in industry.

Multi-reactor systems with aromatization reactor vessels containing a catalyst with low surface area and pore volume, followed in series by aromatization reactor vessels containing a catalyst with high surface area and pore volume, are disclosed. Related reforming methods using the different aromatization catalysts also are described.

Multi-reactor systems with aromatization reactor vessels containing a catalyst with low surface area and pore volume, followed in series by aromatization reactor vessels containing a catalyst with high surface area and pore volume, are disclosed. Related reforming methods using the different aromatization catalysts also are described.