A supported silver catalyst and use thereof in a process for producing an alkylene oxide, such as ethylene oxide, by the direct oxidation of an alkylene with oxygen or an oxygen-containing gas, wherein the catalyst provides improved stability and improved resilience to reactor upsets and timely recovery to substantially pre-upset levels of catalyst activity and/or efficiency. In some embodiments, the catalyst also exhibits improved activity. A catalyst capable of producing ethylene oxide at a selectivity of at least 87 percent while achieving a work rate of at least 184 kg/h/m.sup.3 at a temperature of no greater than 235 C. when operated in a process where the inlet feed to a reactor containing the catalyst comprises ethylene, oxygen, and carbon dioxide, wherein the concentration of carbon dioxide in the inlet feed is greater than or equal to 2 mole percent.

A method for preparing acrylic acid, more specifically, to a method for preparing acrylic acid under a neutral condition at high yield in a short time without using a base, unlike the prior art in which a base is essentially used. The acrylic acid is produced using a supported catalyst having a specific composition when preparing acrylic acid by oxidation of allyl alcohol. Particularly, the preparation method can recover acrylic acid rather than acrylic acid salt as a final product, and thus has an advantage that the overall process cost can be reduced by eliminating essential processes in the prior art, such as ion exchange after the acidification process required for the conversion of acrylic acid salt to acrylic acid.

Catalysts for oxidative esterification can be used, for example, for converting (meth)acrolein to methyl (meth)acrylate. The catalysts are especially notable for high mechanical and chemical stability even over very long time periods, including activity and/or selectivity relatively in continuous operation in media having even a small water content.

A photocatalytic functional film has a structure of a substrate, a barrier layer and a photocatalytic layer stacked one on another. The barrier layer is an amorphous TiO.sub.2 film, the photocatalyst layer comprises an amorphous TiO.sub.2 film, and particles of visible light responsive photocatalytic material formed on the surface of the amorphous TiO.sub.2 film. A method for producing a photocatalytic functional film includes: adding an alcohol solvent and an acid to a titanium precursor to obtain a TiO.sub.2 amorphous sol by dehydration and de-alcoholization reaction; applying and drying the TiO.sub.2 amorphous sol on a substrate to form a barrier layer; and applying and drying a composition formed by mixing particles of visible light responsive photocatalyst material with the TiO.sub.2 amorphous sol on the barrier layer, to form a photocatalyst layer.

Described herein are heterogeneous materials comprising a p-type semiconductor comprising two metal oxide compounds of the same metal in two different oxidation states and an n-type semiconductor having a deeper valence band than the p-type semiconductor valence bands, wherein the semiconductor types are in ionic communication with each other. The heterogeneous materials enhance photocatalytic activity.

Disclosed herein are methods of using scaled selectivities to assist in determining whether changes to the value of a target ethylene oxide production parametersuch as ethylene oxide production rateused in the process of epoxidizing ethylene with a high-selectivity catalyst, have caused the process to move away from optimal operation. If the deviation from optimal operation has not worsened, it is generally unnecessary to perform a full optimization study even if the value of a target ethylene oxide production parameter has changed, which reduces or eliminates process disturbances caused by carrying out such studies. Methods are also disclosed which use both scaled selectivities and scaled reaction temperatures. If scaled selectivities reveal that a change in the value of a target ethylene oxide production parameter has moved the process away from optimal operation, scaled reaction temperatures can, under certain conditions, provide an indication of the directions in which the reaction temperature and/or overall catalyst chloriding effectiveness should be changed to move toward optimal operation. If a change in the value of a target ethylene oxide production parameter has improved the scaled selectivity, the scaled reaction temperature may also be used to guide further adjustments which may further improve scaled selectivity.

A catalyst including gold, or a compound thereof, and sulphur, a compound of sulphur, trichloroisocyanuric acid or a metal dichloroisocyanurate on a support, together with a process for manufacturing the catalyst and its use in a chemical process are described.

A catalyst including gold, or a compound thereof, and sulphur, a compound of sulphur, trichloroisocyanuric acid or a metal dichloroisocyanurate on a support, together with a process for manufacturing the catalyst and its use in a chemical process are described.

The invention relates to a process for conversion of a stream comprising methane and ethane, comprising converting ethane from a stream comprising methane and ethane, in which stream the volume ratio of methane to ethane is of from 0.005:1 to 100:1, to a product having a vapor pressure at 0 C. lower than 1 atmosphere, resulting in a stream comprising methane and the product having a vapor pressure at 0 C. lower than 1 atmosphere; separating the product having a vapor pressure at 0 C. lower than 1 atmosphere from the stream comprising methane and the product having a vapor pressure at 0 C. lower than 1 atmosphere, resulting in a stream comprising methane; and chemically converting methane from the stream comprising methane, or feeding methane from the stream comprising methane to a network that provides methane as energy source, or liquefying methane from the stream comprising methane.

The present disclosure is directed to the preparation of silver-based HSCs. During preparation of the catalyst a selected carrier is co-impregnated with a solution containing a catalytically effective amount of silver and a promoting amount of rhenium and other promoters. After co-impregnation, the carrier is subjected to a separate heat treatment prior to calcination. Such heat treatment is conducted for between about 1 minute and about 120 minutes at temperatures between about 40 C. and about 300 C. Catalysts prepared by the present methodology evidence improved selectivity, activity and/or stability resulting in an increase in the useful life of the catalyst.