A catalyst may suppress pressure loss and coaking and produce a target substance in high yield when a gas-phase catalytic oxidation reaction of a material substance is conducted using the catalyst to produce the target substance. A ring-shaped catalyst may have a straight body part and a hollow body part, which is used when a gas-phase catalytic oxidation reaction of a material substance is conducted to produce a target substance, wherein a length of the straight body part is shorter than a length of the hollow body part and at least at one end part, a region from an end part of the straight body part to an end part of the hollow body part is concavely curved.

An object of the present invention is to provide a catalyst ensuring that when a gas-phase catalytic oxidation reaction of a material substance is conducted using a catalyst to produce a target substance, the pressure loss and coking are suppressed and the target substance can be produced in high yield. The present invention is related to a ring-shaped catalyst having a straight body part and a hollow body part, which is used when a gas-phase catalytic oxidation reaction of a material substance is conducted to produce a target substance, wherein a length of the straight body part is shorter than a length of the hollow body part and at least at one end part, a region from an end part of the straight body part to an end part of the hollow body part is concavely curved.

The present disclosure relates to a process for stabilizing an antimony ammoxidation catalyst in an ammoxidation process. The process may comprise providing an antimony ammoxidation catalyst to a reactor; reacting propylene with ammonia and oxygen in the fluidized bed reactor in the presence of the antimony ammoxidation catalyst to form a crude acrylonitrile product; and adding an effective amount of an antimony-containing compound to the antimony ammoxidation catalyst to maintain catalyst conversion and selectivity; wherein the antimony-containing compound has a melting point less than 375° C. The present disclosure also relates to catalyst compositions and additional processes using the antimony ammoxidation catalyst stabilized by an antimony-containing compound.

The present disclosure relates to a process for stabilizing an antimony ammoxidation catalyst in an ammoxidation process. The process may comprise providing an antimony ammoxidation catalyst to a reactor; reacting propylene with ammonia and oxygen in the fluidized bed reactor in the presence of the antimony ammoxidation catalyst to form a crude acrylonitrile product; and adding an effective amount of an antimony-containing compound to the antimony ammoxidation catalyst to maintain catalyst conversion and selectivity; wherein the antimony-containing compound has a melting point less than 375° C. The present disclosure also relates to catalyst compositions and additional processes using the antimony ammoxidation catalyst stabilized by an antimony-containing compound.

The present invention relates to a hydrocarbon synthesis catalyst comprising in its unreduced form a) Fe as catalytically active metal, b) an alkali metal and/or alkaline-earth metal in an alkali metal- and/or alkaline-earth metal-containing promoter, the alkali metal, c) and a further promoter comprising, or consisting of, one or more element(s) selected from the group of boron, germanium, nitrogen, phosphorus, arsenic, antimony, sulphur, selenium and tellurium, to a process for the synthesis of a hydrocarbon synthesis catalyst, to a hydrocarbon synthesis process which is operated in the present of such a catalyst and to the use of such a catalyst in a hydrocarbon synthesis process.

Disclosed are an electrochemical catalyst capable of lowering the overpotential of the oxygen evolution reaction (OER) during a water splitting reaction in spite of using inexpensive metals (specifically, base metals) instead of conventional noble metal catalysts in the complex water-splitting reactions that require high overpotential, and a water splitting system using the same.

The present invention relates to a hydrocarbon synthesis catalyst comprising in its unreduced form a) Fe as catalytically active metal, b) an alkali metal and/or alkaline-earth metal in an alkali metal- and/or alkaline-earth metal-containing promoter, the alkali metal, c) and a further promoter comprising, or consisting of, one or more element(s) selected from the group of boron, germanium, nitrogen, phosphorus, arsenic, antimony, sulphur, selenium and tellurium, to a process for the synthesis of a hydrocarbon synthesis catalyst, to a hydrocarbon synthesis process which is operated in the present of such a catalyst and to the use of such a catalyst in a hydrocarbon synthesis process.

The present disclosure relates to a process for stabilizing an antimony ammoxidation catalyst in an ammoxidation process. The process may comprise providing an antimony ammoxidation catalyst to a reactor; reacting propylene with ammonia and oxygen in the fluidized bed reactor in the presence of the antimony ammoxidation catalyst to form a crude acrylonitrile product; and adding an effective amount of an antimony-containing compound to the antimony ammoxidation catalyst to maintain catalyst conversion and selectivity; wherein the antimony-containing compound has a melting point less than 375° C. The present disclosure also relates to catalyst compositions and additional processes using the antimony ammoxidation catalyst stabilized by an antimony-containing compound.

An object of the present invention is to provide a catalyst ensuring that in the case of causing gas-phase catalytic oxidation of an unsaturated aldehyde and an oxygen-containing gas with use of the catalyst to produce a corresponding unsaturated carboxylic acid, the pressure loss can be kept low and an unsaturated carboxylic acid can be produced with high selectivity. The present invention relates to a ring-shaped or columnar catalyst, which is used at the time of producing a corresponding unsaturated carboxylic acid by causing gas-phase catalytic oxidation of an unsaturated aldehyde and an oxygen-containing gas, wherein the outer peripheral edge part is inclined relative to the center line.

The present disclosure relates to a process for stabilizing an antimony ammoxidation catalyst in an ammoxidation process. The process may comprise providing an antimony ammoxidation catalyst to a reactor; reacting propylene with ammonia and oxygen in the fluidized bed reactor in the presence of the antimony ammoxidation catalyst to form a crude acrylonitrile product; and adding an effective amount of an antimony-containing compound to the antimony ammoxidation catalyst to maintain catalyst conversion and selectivity; wherein the antimony-containing compound has a melting point less than 375 C. The present disclosure also relates to catalyst compositions and additional processes using the antimony ammoxidation catalyst stabilized by an antimony-containing compound.