A cluster-supporting catalyst including porous carrier particles having acid sites, and catalyst metal clusters supported within the pores of the porous carrier particles. The catalyst metal clusters are obtained by supporting catalyst metal clusters having a positive charge, which is formed in a dispersion liquid containing a dispersion medium and the porous carrier particles dispersed in the dispersion medium, on the acid sites within the pores of the porous carrier particles through an electrostatic interaction.

A heterogeneous catalyst comprising a metal-containing polymer matrix covalently bonded to a support material and a method of making and using such catalysts. The metal-containing polymer matrix comprises metal nano-particles encapsulated in a polymer matrix, e.g., a siloxane. In one aspect, the metal-containing polymer matrix can be bonded to the support material via a hydrophobic group attached to the support material. The catalyst can be recovered after being used in a metal catalyzed reaction and exhibit excellent catalytic activity upon reuse in subsequent reactions.

Photocatalyst compositions and elements exhibiting desired photocatalytic activity levels and transparency.

A catalyst comprises an active phase constituted by palladium, and a porous support comprising at least one refractory oxide selected from the group constituted by silica, alumina and silica-alumina, in which: the palladium content in the catalyst is in the range 0.0025% to 1% by weight with respect to the total weight of catalyst; at least 80% by weight of the palladium is distributed in a crust at the periphery of the porous support, the thickness of said crust being in the range 25 to 450 m; the specific surface area of the porous support is in the range 70 to 160 m.sup.2/g; the metallic dispersion D of the palladium is less than 20%.

The present invention is in the field of catalysis. More particularly, the present invention is directed to supported precious metal catalysts, preferably palladium and/or platinum metal catalysts, having a high metal loading, a high degree of dispersion and a high degree of edge-coating. The present invention is further directed to a process for producing these catalysts, as well as to the use of these catalysts in chemical reactions.

The present invention is in the field of catalysis. More particularly, the present invention is directed to supported precious metal, preferably palladium and/or gold metal catalysts, having a high degree of dispersion and a high degree of edge-coating. The present invention is further directed to a process for producing these catalysts, as well as to the use of these catalysts in chemical reactions.

There is provided a water purification catalyst element (100). The catalyst element (100) comprises a porous support (102) having a first surface (106) and a second surface (110). The first or the second surface (106, 110) delimit a conduit (114) through the catalyst element (100). A material (104) comprising a noble metal is supported on the porous support (102). At least the first surface (106) is coated with a coating material (108) permeable to hydrogen gas and impermeable to water, and at least the second surface (110) is water-permeable. This catalyst element (100) can selectively convert nitrites and/or nitrates to N.sub.2 gas and can be used to provide a cost efficient and/or maintenance free water purification setup. There is also provided a water purifier (200) comprising the catalyst element (100), a beverage maker (300) comprising the water purifier (200), a method (1800) of water purification and a method (1900) of making the catalyst element (100).

An objective of the present invention is to provide a method for producing a catalyst for exhaust gas removal having excellent heat tolerance and purification performance within a wide range of atmospheres and a catalyst obtained by the production method. The present invention relates to a method for supporting catalyst metal particles, comprising: (a) adding an iridium precursor and a palladium precursor to a solvent containing at least one member selected from the group consisting of polyvinylpyrrolidone, N-methylpyrrolidone, N-vinyl-2-pyrrolidone, and ethylene glycol; (b) adding a reducing agent to the obtained catalyst metal colloid; (c) obtaining a concentrated solution containing catalyst metal particles by subjecting the obtained solution to heat reflux; and (d) supporting the catalyst metal particles on a carrier, wherein the iridium content of the catalyst metal particles accounts for 3% to 10% by mass of the total mass of iridium and palladium.

A catalyst comprising gold, palladium, and a porous support, in the form of at least one grain, in which: the gold content in the catalyst is in the range 0.5% to 3% by weight with respect to the total weight of catalyst; the mean particle size of the gold, estimated by transmission electron microscopy (TEM), is in the range 0.5 nm to 5 nm; the gold is distributed homogeneously in said porous support; at least 80% by weight of the palladium is distributed in an eggshell at the periphery of said porous support; the gold/palladium molar ratio is more than 2.

Catalytic materials, and in particular, rhodium-containing catalytic materials for exhaust gas purifying catalyst composites are provided herein. Such materials comprise multimetallic Rh-containing nanoparticles, which are present primarily inside aggregated particles of a support (such as alumina). Such catalytic materials can exhibit excellent conversion of hydrocarbons and nitrogen oxides.