Catalyst preparation systems and methods for preparing reduced chromium catalysts are disclosed, and can comprise irradiating a supported chromium catalyst containing hexavalent chromium with a light beam having a wavelength within the UV-visible light spectrum. Such reduced chromium catalysts have improved catalytic activity compared to chromium catalysts reduced by other means. The use of the reduced chromium catalyst in polymerization reactor systems and olefin polymerization processes also is disclosed, resulting in polymers with a higher melt index.

Catalyst preparation systems and methods for preparing reduced chromium catalysts are disclosed, and can comprise irradiating a supported chromium catalyst containing hexavalent chromium with a light beam having a wavelength within the UV-visible light spectrum. Such reduced chromium catalysts have improved catalytic activity compared to chromium catalysts reduced by other means. The use of the reduced chromium catalyst in polymerization reactor systems and olefin polymerization processes also is disclosed, resulting in polymers with a higher melt index.

A method and apparatus for: providing a ceria aerogel and copper nanoparticle catalyst, flowing a hydrogen, carbon monoxide, and water vapor source gas from an inlet into contact with the catalyst to produce a product gas, and flowing the product gas to an outlet. The concentration of carbon monoxide in the product gas is no more than 50% of the concentration of carbon monoxide in the source gas. The concentration of hydrogen in the product gas is no less than 90% of the concentration of hydrogen in the source gas.

Metal oxide nanoarrays, such as titanium oxide nanoarrays, having a platinum group metal dispersed thereon and methods of making such nanoarrays are described. The platinum group metal can be dispersed on the metal oxide nanoarray as single atoms. The nanoarrays can be used to catalyze oxidation of combustion exhaust.

Disclosed are a metal single-atom catalyst and a method for preparing the same. The method uses a minimal amount of chemicals and is thus environmentally friendly compared to conventional chemical and/or physical methods. In addition, the method enables the preparation of a single-atom catalyst in a simple and economical manner without the need for further treatment such as acid treatment or heat treatment. Furthermore, the method is universally applicable to the preparation of single-atom catalysts irrespective of the kinds of metals and supports, unlike conventional methods that suffer from very limited choices of metal materials and supports. Therefore, the method can be widely utilized to prepare various types of metal single-atom catalysts. All metal atoms in the metal single-atom catalyst can participate in catalytic reactions. This optimal atom utilization achieves maximum reactivity per unit mass and can minimize the amount of the metal used, which is very economical.

Process for the preparation of a TiO.sub.2 photocatalyst/biomass carrier, with TiO.sub.2/M.sub.xO.sub.y nanocrystals, of at least nanometric size and photocatalysis-active at least in visible light, consisting of the following steps: a) preparation and heating of an aqueous solution of hydrochloric acid with a given pH, between 0 and 6, and at a temperature between 20° C. and 60° C., with no surfactant, b) addition to the acidic aqueous solution of the titanium oxide precursor, or the mixture of a TiO.sub.2 titanium oxide precursor and at least one other precursor of another M.sub.xO.sub.y oxide, consisting, 80% to 100%, of TiO.sub.2 moles and 0% to 20% of moles of another metal or semi-metal M.sub.xO.sub.y oxide, a precipitate then forming, and stirring of the acidic aqueous reaction medium obtained, so as to dissolve the precipitate; c) an immersing step of the carrier in the acidic aqueous reaction medium, d) a heating step of the acidic aqueous reaction medium, the carrier for crystallizing the titanium oxide precursors, or the mixture of the titanium oxide precursor and at least one other precursor of the other metal or semi-metal oxide, e) a possible water rinse step and a biomass carrier recovery step with TiO.sub.2/M.sub.xO.sub.y nanocrystals, bound by covalent bonds to the biomass carrier.

A metal-supported nonwoven fabric is provided which enables effective synthesis of a target product when used as a catalyst in a flow reaction. The metal-supported nonwoven fabric comprises a nonwoven fabric containing polyolefin fibers or PET fibers, and metal particles. The nonwoven fabric has grafted side chains bound thereto formed of polyvinylpyrrolidone, polyacrylic acid, or a polymer containing functional groups with unshared electron pairs. The metal particles are supported by the grafted side chains via pyrrolidone groups of the polyvinylpyrrolidone, carboxy groups of the polyacrylic acid, or the functional groups with unshared electron pairs.

A multifunctional self-cleaning surface layer and methods of preparing the multifunctional self-cleaning surface layer are provided. The multifunctional self-cleaning surface layer includes an inorganic matrix including silicon and oxygen; a plurality of photocatalytic active particles distributed within and bonded to the inorganic matrix; and a plurality of nanopores defined within the inorganic matrix in regions corresponding to bonds between the plurality of photocatalytic active particles and the inorganic matrix. Water molecules may be disposed within at least a portion of the plurality of nanopores. In the presence of water and electromagnetic radiation, the plurality of photocatalytic active particles may facilitate a decomposition reaction of any oil or organic residue on the multifunctional self-cleaning surface layer.

Supported chromium catalysts with an average valence less than +6 and having a hydrocarbon-containing or halogenated hydrocarbon-containing ligand attached to at least one bonding site on the chromium are disclosed, as well as ethylene-based polymers with terminal alkane, aromatic, or halogenated hydrocarbon chain ends. Another ethylene polymer characterized by at least 2 wt. % of the polymer having a molecular weight greater than 1,000,000 g/mol and at least 1.5 wt. % of the polymer having a molecular weight less than 1000 g/mol is provided, as well as an ethylene homopolymer with at least 3.5 methyl short chain branches and less than 0.6 butyl short chain branches per 1000 total carbon atoms.

Aspects of the present disclosure generally relate to catalyst compositions including metal chalcogenides, processes for producing such catalyst compositions, processes for enhancing catalytic active sites in such catalyst compositions, and uses of such catalyst compositions in, e.g., processes for producing conversion products. In an aspect, a process for forming a catalyst composition is provided. The process includes introducing an electrolyte material and an amphiphile material to a metal chalcogenide to form the catalyst composition. In another aspect, a catalyst composition is provided. The catalyst composition includes a metal chalcogenide, an electrolyte material, and an amphiphile material. Devices for hydrogen evolution reaction are also provided.