The sunlight active composite photocatalyst for water purification includes ZnO (zinc oxide) and Co.sub.3O.sub.4 (cobalt II, III oxide). The composite photocatalyst may, in the presence of natural sunlight, achieve complete mineralization of chemical and biological contaminants in water without leaving any hazardous by-products. The composite photocatalyst may be synthesized by a sol gel route or process.

The present invention discloses a fast and selective process for the preparation of γ-valerolactone (Gvl) by catalytic hydrogenation of biomass-derived levulinic acid (LA) using recyclable ruthenium (Ru)-based heterogeneous catalysts in aqueous medium in stoichiometric yields (100%) under mild reaction conditions using nearly required amount of hydrogen.

Embodiments of the present disclosure provide for substrates having an oxide shell layer (e.g., a silica shell layer), methods of making an oxide shell layer, and the like.

Disclosed is a method for preparing a material of plant origin rich in phenolic acids, including at least one metal, including: preparing a material of plant origin chosen from: aquatic plants; materials rich in tannins; materials rich in lignin; and obtaining a material of plant origin, rich in phenolic acids, in which the ratio of the intensity of the vibration band of the C═O bond of the COOH group and the intensity of each of the vibration bands the aromatic ring determined in FT-IR is between 0.5 and 4. The material of plant origin is brought into contact with an effluent including from 0.1 to 1000 mg/l of at least one metal, thus obtaining a material of plant origin rich in phenolic acids including from 1 to 30% by weight of at least one metal relative to the total weight of the material.

Solid base catalysts and their use for the base-catalyzed depolymerization (BCD) of lignin to compounds such as aromatics are presented herein. Exemplary catalysts include layered double hydroxides (LDHs) as recyclable, heterogeneous catalysts for BCD of lignin.

A catalyst composition comprising a mixture of (a) a zeolite compound in an amount of from 10% to 60% by weight, wherein the zeolite compound comprises cations selected from Fe.sup.2+, Fe.sup.3+, Cu.sup.+, Cu.sup.2+ or mixtures thereof, and (b) a ceria/zirconia/alumina composite oxide, wherein the alumina content in said composite oxide is in the range of 20 to 80% by weight, in particular of 40 to 60% by weight,
a catalyst comprising such catalyst composition and its use for exhaust gas after-treatment of diesel and lean burn engines.

A method of producing an ethylenically unsaturated carboxylic acid or ester such as (meth) acrylic acid or alkyl esters thereof, for example, methyl methacrylate is described. The process comprises the steps of contacting formaldehyde or a suitable source thereof with a carboxylic acid or ester, for example, propionic acid or alkyl esters thereof in the presence of a catalyst and optionally an alcohol. The catalyst comprises group II metal phosphate crystals having rod or needle like morphology or a suitable source thereof. The phosphate may be a hydroxyapatite, pyrophosphate, hydroxyphosphate, PO.sub.4.sup.2− phosphate or mixtures thereof. The group II metal may be selected from Ca, Sr, Ba or mixtures thereof, for example, strontium hydroxyapatite and calcium hydroxyapatite. A catalyst system comprising a crystalline metal phosphate catalyst and a catalyst support is also described. The metal phosphate has rod/needle like morphology.

A method of producing an ethylenically unsaturated carboxylic acid or ester such as (meth) acrylic acid or alkyl esters thereof, for example, methyl methacrylate is described. The process comprises the steps of contacting formaldehyde or a suitable source thereof with a carboxylic acid or ester, for example, propionic acid or alkyl esters thereof in the presence of a catalyst and optionally an alcohol. The catalyst comprises group II metal phosphate crystals having rod or needle like morphology or a suitable source thereof. The phosphate may be a hydroxyapatite, pyrophosphate, hydroxyphosphate, PO.sub.4.sup.2− phosphate or mixtures thereof. The group II metal may be selected from Ca, Sr, Ba or mixtures thereof, for example, strontium hydroxyapatite and calcium hydroxyapatite. A catalyst system comprising a crystalline metal phosphate catalyst and a catalyst support is also described. The metal phosphate has rod/needle like morphology.

Method for producing a substrate with Au (gold) nanoclusters affixed to the surface thereof and substrate and catalyst obtained by means of said method. The method consists in preparing a solution containing, in disperse form, Au nanoclusters and, also in disperse form, a substrate with a surface functionalized with a polyelectrolyte that confers a net electric charge thereon, and in intensely agitating said solution to affix Au nanoclusters to the substrate surface. This results in a substrate that has a surface with Au nanoclusters affixed in disperse form, significantly without clusters. The invention also relates to a catalyst that comprises said substrate with Au nanoclusters affixed to the surface thereof. Said catalyst is particularly suitable for use in oxidation reactions.

The present invention provides a catalyst for the decomposition of nitrous oxide, said catalyst comprising oxides of cobalt, zinc and aluminum and an alkali metal promoter.