Provided herein are photocatalytic carbon filters for the removal impurities such as microorganisms, organic compounds, algal toxins, and their degradation by-products from water and wastewater. The photolytic carbon filters comprise a porous titanium substrate comprising TiO.sub.2 nanotube arrays and multi-wall carbon nanotubes disposed on the TiO.sub.2 nanotube arrays. Also provided herein are methods of manufacture and methods of use of the disclosed photocatalytic carbon filters.

A low-platinum catalyst based on nitride nanoparticles and a preparation method thereof. A component of an active metal of the catalyst directly clades on a surface of nitride particles or a surface of nitride particles loaded on a carbon support in an ultrathin atomic layer form. Preparation steps including: preparing a transition-metal ammonia complex first, nitriding the obtained ammonia complex solid under an atmosphere of ammonia gas to obtain nitride nanoparticles; loading the nitride nanoparticles on a surface of a working electrode, depositing an active component on a surface of the nitride nanoparticles by pulsed deposition, to obtain the low platinum loading catalyst using a nitride as a substrate. The catalyst may be used as an anode or a cathode catalyst of a low temperature fuel cell.

A method for reducing nitrates, nitrites, and/or hydroxylamine in water using a homogeneous reduced copper tetra-substituted fluorinated pinacolate ligand catalyst complex. The method includes dissolving a copper(II) tetra-substituted fluorinated pinacolate ligand pre-catalyst complex in water having an excess amount of nitrates, nitrites, and/or hydroxylamine therein. The dissolved copper(II) tetra-substituted fluorinated pinacolate ligand pre-catalyst complex in the water is subjected to electrochemical reduction to form a homogeneous reduced copper tetra-substituted fluorinated pinacolate ligand catalyst complex. The homogeneous reduced copper tetra-substituted fluorinated pinacolate ligand catalyst complex reduces the nitrates, nitrites, and/or hydroxylamine in the water to compounds with nitrogen in a lower oxidation state with the homogeneous reduced copper tetra-substituted fluorinated pinacolate ligand catalyst complex.

A hydrocracking catalyst for petroleum hydrocracking is provided, the hydrocracking catalyst provided in a form of at least one fiber, and the at least one fiber comprising at least one zeolite and at least one metal oxide. Methods are also provided to form the hydrocracking catalyst in the form of at least one fiber, particularly electrospinning.

A stereostructure includes a core portion, and a porous portion located around the core portion. The porous portion located inside a position which is inside from an outer edge of the porous portion by 3/20 of a diameter of the stereostructure in an arbitrary cross section of the stereostructure has a void ratio per unit area of less than or equal to 80%.

A nanofibrous catalyst for in the electrolyzer and methods of making the catalyst. The catalysts are composed of highly porous transition metal carbonitrides, metal oxides or perovskites derived from the metal-organic frameworks and integrated into a 3D porous nano-network electrode architecture. The catalysts are low-cost, highly active toward OER, with excellent conductivity yet resistant to the oxidation under high potential operable under both acidic and alkaline environments.

A metal porous body has a skeleton of a three-dimensional network structure, an outer layer portion of the skeleton having a second pore smaller in size than a first pore formed by the skeleton, wherein the outer layer portion is a metal layer, and a water vapor reforming catalyst is supported in the outer layer portion.

Disclosed is a method for forming a catalyst bed for catalytic decomposition of hydrogen peroxide, which uses 3-D printing techniques to form a porous metal backbone and treating the surface of the metal backbone to activate the surface, wherein the metal backbone is formed of a noble metal or a manganese complex. Also disclosed is a rocket engine having a 3D printed catalyst for catalytic decomposition of hydrogen peroxide, a fuel store, an oxidizer store, and a rocket engine, wherein the oxidizer is a stabilized solution of hydrogen peroxide, and a 3D printed catalyst bed.

A method for forming catalyst particles, each of which has a core/shell structure, by a Cu-UPD method. Namely, a method of manufacturing a catalyst wherein catalyst particles, each of which has a core/shell structure composed of a shell layer that is formed of platinum and a core particle that is covered with the shell layer and is formed of a metal other than platinum, are supported on a carrier. This method is characterized by comprising: an electrolysis step wherein the carrier supporting the core particles is electrolyzed in an electrolytic solution containing copper ions, so that copper is precipitated on the surfaces of the core particles; and a substitution reaction step wherein a platinum compound solution is brought into contact with the core particles, on which copper has been precipitated, so that the copper on the surface of each core particle is substituted by platinum, thereby forming a shell layer that is formed of platinum. This method is further characterized in that the platinum compound solution in the substitution reaction step contains citric acid.

Provided is a method of manufacturing a nano-catalyst filter, which includes depositing through electrodeposition a catalyst precursor inside a porous filter to which an electrode layer is attached. Using this method, a nano-catalyst can be uniformly deposited inside a porous ceramic filter, and high catalyst efficiency can be obtained only using a small amount of the nano-catalyst.