The invention relates to poly oxometalates represented by the formula (A.sub.n).sup.m+{M.sub.s[MM.sub.15X.sub.10O.sub.yR.sub.zH.sub.q]}.sup.m or solvates thereof, corresponding supported polyoxometalates, and processes for their preparation, as well as corresponding metal-clusters, optionally in the form of a dispersion in a liquid carrier medium or immobilized on a solid support, and processes for their preparation, as well as their use in reductive conversion of organic substrate.

The invention relates to poly oxometalates represented by the formula (A.sub.n).sup.m+{M.sub.s[MM.sub.15X.sub.10O.sub.yR.sub.zH.sub.q]}.sup.m or solvates thereof, corresponding supported polyoxometalates, and processes for their preparation, as well as corresponding metal-clusters, optionally in the form of a dispersion in a liquid carrier medium or immobilized on a solid support, and processes for their preparation, as well as their use in reductive conversion of organic substrate.

Disclosed is a catalyst which can be used in the process for producing hydrogen by decomposing ammonia, can generate heat efficiently in the interior of a reactor without requiring excessive heating the reactor externally, and can decompose ammonia efficiently and steadily by utilizing the heat to produce hydrogen. Also disclosed is a technique for producing hydrogen by decomposing ammonia efficiently utilizing the catalyst. Specifically disclosed is a catalyst for use in the production of hydrogen, which is characterized by comprising an ammonia-combusting catalytic component and an ammonia-decomposing catalytic component. Also specifically disclosed is a catalyst for use in the production of hydrogen, which is characterized by comprising at least one metal element selected from the group consisting of cobalt, iron, nickel and molybdenum.

Disclosed is a catalyst which can be used in the process for producing hydrogen by decomposing ammonia, can generate heat efficiently in the interior of a reactor without requiring excessive heating the reactor externally, and can decompose ammonia efficiently and steadily by utilizing the heat to produce hydrogen. Also disclosed is a technique for producing hydrogen by decomposing ammonia efficiently utilizing the catalyst. Specifically disclosed is a catalyst for use in the production of hydrogen, which is characterized by comprising an ammonia-combusting catalytic component and an ammonia-decomposing catalytic component. Also specifically disclosed is a catalyst for use in the production of hydrogen, which is characterized by comprising at least one metal element selected from the group consisting of cobalt, iron, nickel and molybdenum.

The invention relates to a catalyst composition, suitable for producing ethylene and other commercially high value C.sub.2+ hydrocarbons from methane. The composition contains a silver promoted mixed metal catalyst composition comprising at least two rare earth elements and an alkaline rare earth metal element. The catalyst composition has high catalyst activity and enables oxidative coupling of methane reactions to be conducted at a low reactor temperature while retaining sufficient catalyst selectivity. The invention further provides a method for preparing such a catalyst composition and a process for producing C.sub.2+ hydrocarbons, using such a catalyst composition.

The invention relates to a catalyst composition, suitable for producing ethylene and other commercially high value C.sub.2+ hydrocarbons from methane. The composition contains a silver promoted mixed metal catalyst composition comprising at least two rare earth elements and an alkaline rare earth metal element. The catalyst composition has high catalyst activity and enables oxidative coupling of methane reactions to be conducted at a low reactor temperature while retaining sufficient catalyst selectivity. The invention further provides a method for preparing such a catalyst composition and a process for producing C.sub.2+ hydrocarbons, using such a catalyst composition.

The present invention refers to lightweight and settable photocatalytic compositions and solid composites; methods of preparing the compositions and solid composites; and their use in water purification. The compositions are comprised of photocatalysts such as titanium dioxide (TiO.sub.2) and zinc oxide (ZnO), lightweight glass bubbles, and a hydraulic cementing binder. The lightweight and settable photocatalytic compositions can be formed into lightweight photocatalytic solid composites and/or structures by mixing with water and moist curing. This invention also describes relatively simple, fast, and cost effective methodologies to photodope the TiO.sub.2ZnO compositions and composites with silver (Ag), to enhance and extend the photocatalytic activity from the ultraviolet into the visible light spectrum. The lightweight and settable TiO.sub.2ZnO and AgTiO.sub.2ZnO compositions are used in making solids, structures, coatings, and continuous or semi-continuous water purification panels for purifying contaminated water.

The present invention refers to lightweight and settable photocatalytic compositions and solid composites; methods of preparing the compositions and solid composites; and their use in water purification. The compositions are comprised of photocatalysts such as titanium dioxide (TiO.sub.2) and zinc oxide (ZnO), lightweight glass bubbles, and a hydraulic cementing binder. The lightweight and settable photocatalytic compositions can be formed into lightweight photocatalytic solid composites and/or structures by mixing with water and moist curing. This invention also describes relatively simple, fast, and cost effective methodologies to photodope the TiO.sub.2ZnO compositions and composites with silver (Ag), to enhance and extend the photocatalytic activity from the ultraviolet into the visible light spectrum. The lightweight and settable TiO.sub.2ZnO and AgTiO.sub.2ZnO compositions are used in making solids, structures, coatings, and continuous or semi-continuous water purification panels for purifying contaminated water.

A process for the preparation of a catalyst comprising palladium, a porous support with a specific surface area in the range 140 to 250 m.sup.2/g, said catalyst being prepared by a process comprising the following steps: a) preparing a colloidal solution of palladium oxide or palladium hydroxide in an aqueous phase; b) adding said solution obtained from step a) to said porous support at a flow rate in the range 1 to 20 litre(s)/hour; said porous support being contained in a rotary impregnation device functioning at a rotational speed in the range 10 to 20 rpm; c) optionally, submitting the impregnated porous support obtained from step b) to a maturation; d) drying the catalyst precursor obtained from step b) or c); e) calcining the catalyst precursor obtained from step d).

A process for the preparation of a catalyst comprising palladium, a porous support with a specific surface area in the range 140 to 250 m.sup.2/g, said catalyst being prepared by a process comprising the following steps: a) preparing a colloidal solution of palladium oxide or palladium hydroxide in an aqueous phase; b) adding said solution obtained from step a) to said porous support at a flow rate in the range 1 to 20 litre(s)/hour; said porous support being contained in a rotary impregnation device functioning at a rotational speed in the range 10 to 20 rpm; c) optionally, submitting the impregnated porous support obtained from step b) to a maturation; d) drying the catalyst precursor obtained from step b) or c); e) calcining the catalyst precursor obtained from step d).