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.

A photocatalytic device includes a substrate having a surface, and an array of conductive projections supported by the substrate and extending outward from the surface of the substrate. Each conductive projection of the array of conductive projections has a semiconductor composition. The semiconductor composition establishes a photochemical diode. The surface may be nonplanar such that subsets of the array of conductive projections are oriented at different angles.

A photocatalytic device includes a substrate having a surface, and an array of conductive projections supported by the substrate and extending outward from the surface of the substrate. Each conductive projection of the array of conductive projections has a semiconductor composition. The semiconductor composition establishes a photochemical diode. The surface may be nonplanar such that subsets of the array of conductive projections are oriented at different angles.

A method for ambient-temperature synthesis of a catalyst for water electrolysis by dissolving an amount of an Fe.sup.2+ source and optionally an amount of a salt of another divalent cation in deionized water at ambient temperature to form a solution, placing nickel (Ni) foam into the solution, whereby the Ni foam serves as a substrate and/or a Ni source for growth of the catalyst, leaving the Ni foam in the solution at ambient temperature for a time duration in a range of from about 0.5 hour to about 4 hours to provide a treated foam, during which time duration, the catalyst is grown on the substrate, and removing the treated foam from the solution after the time duration, wherein the treated foam comprises the catalyst grown thereon.

The invention relates to a method of regenerating the catalytic activity of a spent catalyst comprising nickel on a refractory oxide support, said method comprising the steps of contacting the spent catalyst with a nitric acid solution, heat-treating the spent catalyst, calcining and reducing the catalyst.

The invention relates to a mixed oxide composed of zirconium, cerium, lanthanum and at least one rare earth oxide other than cerium and lanthanum, having a specific porosity and a high specific surface area; to the method for preparing same and to the use thereof in catalysis.

The invention relates to a mixed oxide composed of zirconium, cerium, lanthanum and at least one rare earth oxide other than cerium and lanthanum, having a specific porosity and a high specific surface area; to the method for preparing same and to the use thereof in catalysis.

A washing device includes executors for executing a normal washing step and a reverse washing step before executing a plate opening step and a cake peeling step. The normal washing step is a step for supplying a washing water to a filter chamber, allowing the washing water to pass through a cake, and then discharging the washing water from filtrate discharge outlets. The reverse washing step is a step for supplying a washing water from the filtrate discharge outlet(s) to the filter chamber, allowing the washing water to pass through the cake, and then discharging the washing water from the filtrate discharge outlet(s) which are different from the filtrate discharge outlet(s) from which the washing water is supplied. The thickness of the electrode catalyst precursor-containing cake at the time of the injection step is adjusted to that of a range that has been previously and experimentally determined.

A catalyst has a carrier and a hydrogenation active metal component supported on the carrier. The hydrogenation active metal component contains at least one Group VIB metal component and at least one Group VIII metal component, and the carrier is composed of phosphorus-containing alumina. When the hydrogenation catalyst is measured using a hydrogen temperature programmed reduction method (H.sub.2-TPR), the ratio of the peak height of the low-temperature reduction peak, P.sub.low-temp peak, at a temperature of 300-500° C. to the peak height of the high-temperature reduction peak, P.sub.hi-temp peak, at a temperature of 650-850° C., i.e. S=P.sub.low-temp peak/P.sub.hi-temp peak, is 0.5-2.0; preferably 0.7-1.9, and more preferably 0.8-1.8. The hydrogenation catalyst shows excellent heteroatom removal effect and excellent stability when used in hydrotreatment.

Cu.sub.y/MMgO.sub.x interfacial catalyst for selective alkyne hydrogenation and its preparation method are disclosed. The preparation method of the catalyst includes: the mixture of salt and alkali solution is nucleated momentarily by nucleation/crystallization isolation method, preparing the composite metal hydroxide Cu.sub.yMMg.sub.4-LDHs as precursor, which has typical hexagonal morphology of the double hydroxide; the precursor is topologically transformed by heat treatment to produce unsaturated oxide; the catalyst with Cu.sub.y-MMgO.sub.x interface structure is prepared by separating and electronically modifying Cu particles. By adjusting the ratio of Cu.sup.2+/M.sup.3+ in LDHs, the electronic and geometric structure of Cu.sub.y-MMgO.sub.x interface can be flexibly controlled, thus enhancing the reaction activity, product selectivity and stability. The catalyst can be used in the selective hydrogenation of various alkynes in the fields of petrochemical and fine chemical industry, with the outstanding catalytic activity and C═C double bond selectivity. The catalyst also has good reusability.