131 results about "Catalyst nanoparticles" patented technology

A catalyst material for carbon nanotube synthesis includes a uniform dispersion of host particles on a substrate. The host particles themselves include catalyst nanoparticles that are effective to catalyze nanotube syntheses reactions and provide nucleation sites. Methods for preparing catalyst materials include co-sputtering a catalytic species and a host species to form a precursor thin film on a substrate, followed by an oxidation reaction of the precursor thin film in air. The precursor thin film can be patterned on the substrate to limit the locations of the catalyst material to well-defined areas. Methods for nanotube synthesis employ CVD in conjunction with the catalyst materials of the invention. During the synthesis, the catalyst nanoparticles catalyze carbon nanotubes to grown from a carbon-containing gas.

Nitrogen-doped titania nanotubes exhibiting catalytic activity on exposure to any one or more of ultraviolet, visible, and/or infrared radiation, or combinations thereof are disclosed. The nanotube arrays may be co-doped with one or more nonmetals and may further include co-catalyst nanoparticles. Also, methods are disclosed for use of nitrogen-doped titania nanotubes in catalytic conversion of carbon dioxide alone or in admixture with hydrogen-containing gases such as water vapor and/or other reactants as may be present or desirable into products such as hydrocarbons and hydrocarbon-containing products, hydrogen and hydrogen-containing products, carbon monoxide and other carbon-containing products, or combinations thereof.

A fluidized-bed reactor comprising a chamber defining a hollow interior region and having a lower surface; a first input for introducing a contaminated gas into the hollow interior region; a plurality of catalyst nanoparticles within the hollow interior region and located on the lower surface, and a fluidizing input for introducing a fluidizing material into the hollow interior region, said fluidizing input having an outlet directed at the lower surface of the chamber, wherein the introduction of the fluidizing material directed at the lower surface fluidizes at least a portion of the catlyst nanoparticles located on the lower surface to create a gaseous dispersion of catalyst nanoparticles that reacts with the contaminated gas to produce a decontaminated gas.

Multilayer carbon nanotube capacitors, and methods and printable compositions for manufacturing multilayer carbon nanotubes (CNTs) are disclosed. A first capacitor embodiment comprises: a first conductor; a plurality of fixed CNTs in an ionic liquid, each fixed CNT comprising a magnetic catalyst nanoparticle coupled to a carbon nanotube and further coupled to the first conductor; and a first plurality of free CNTs dispersed and moveable in the ionic liquid. Another capacitor embodiment comprises: a first conductor; a conductive nanomesh coupled to the first conductor; a first plurality of fixed CNTs in an ionic liquid and further coupled to the conductive nanomesh; and a plurality of free CNTs dispersed and moveable in the ionic liquid. Various methods of printing the CNTs and other structures, and methods of aligning and moving the CNTs using applied electric and magnetic fields, are also disclosed.

A nanowire of a semiconductor material and having a uniform cross-sectional area along its length is grown using a chemical vapor deposition process. In the method, a substrate is provided, a catalyst nanoparticle is deposited on the substrate, a gaseous precursor mixture comprising a constituent element of the semiconductor material is passed over the substrate, and adatoms of the constituent element are removed from a lateral surface of the nanowire during the passing of the precursor mixture. Removing the adatoms of the constituent element before such adatoms are incorporated into the nanowire prevents such adatoms from accumulating on the lateral surface of the nanowire and allows the nanowire to grow with a uniform cross-sectional area along its length.

Preferred embodiments provide a method for forming at least one catalyst nanoparticle on at least one sidewall of a three-dimensional structure on a main surface of a substrate, the main surface lying in a plane and the sidewall of the three-dimensional structure lying in a plane substantially perpendicular to the plane of the main surface of the substrate. The method comprises obtaining a three-dimensional structure on the main surface, the three-dimensional structure comprising catalyst nanoparticles embedded in a non-catalytic matrix and selectively removing at least part of the non-catalytic matrix at the sidewalls of the three-dimensional structure to thereby expose at least one catalyst nanoparticle. According to preferred embodiments a method is also provided for forming at least one elongated nanostructure, such as e.g. a nanowire or carbon nanotube, using the catalyst nanoparticles formed by the method according to preferred embodiments as a catalyst. The methods according to preferred embodiments may be used in, for example, semiconductor processing. The methods according to preferred embodiments are scalable and fully compatible with existing semiconductor processing technology.

An organically complexed nanocatalyst composition is applied to or mixed with coal prior to or upon introducing the coal into a coal burner in order to catalyze the removal of coal nitrogen from the coal and its conversion into nitrogen gas prior to combustion of the coal. This leads to reduced NOx production during coal combustion. The nanocatalyst compositions include a nanoparticle catalyst that is made using a dispersing agent. The dispersing agent includes at least one functional group such as a hydroxyl, a carboxyl, a carbonyl, an amine, an amide, a nitrile, a nitrogen having a free lone pair of electrons, an amino acid, a thiol, a sulfonic acid, a sulfonyl halide, and an. acyl halide. The dispersing agent forms stable, dispersed, nano-sized catalyst particles. The catalyst composition can be formed as a stable suspension to facilitate storage, transportation and application of the catalyst nanoparticles to a coal material. The catalyst composition can be applied before or after pulverizing the coal material or it may be injected directly into the coal burner together with pulverized coal.

A catalyst material for carbon nanotube synthesis includes a uniform dispersion of host particles on a substrate. The host particles themselves include catalyst nanoparticles that are effective to catalyze nanotube syntheses reactions and provide nucleation sites. Methods for preparing a catalyst material includes co-sputtering a catalytic species and a host species to directly form the catalyst material. Methods for synthesizing generally aligned nanotubes are also provided. In these methods host particles comprise alumina and the catalyst nanoparticles comprise iron. Also in these methods nanotube synthesis is achieved in an atmosphere including a carbon-containing gas and water vapor.

A method for forming a CNT infused substrate comprises exposing a catalyst nanoparticle, a carbon feedstock gas, and a carrier gas to a CNT synthesis temperature, allowing a CNT to form on the catalyst nanoparticle, cooling the CNT, and exposing the cooled CNT to a surface of a substrate to form a CNT infused substrate.

The invention provides a transition metal embedded porous nitrogen-phosphorus-doped carbon material, employing agar as a carbon source, metal ions as a fixing agent, and EDTMPA (ethylene diamine tetramethylene phosphoric acid) as a nitrogen and phosphorus source; the porous nitrogen-phosphorus-doped carbon material prepared has co-existing microscopic and mesoscopic structures and metal particles evenly distributed in a carbon carrier. Compared with the prior art, the preparation method according to the invention is simple, the cost of raw materials is low, nitrogen and phosphorus doping efficiency can be improved effectively, the specific surface area of the catalyst nanoparticles can be enlarged effectively, and the prepared porous nitrogen-phosphorus-doped carbon material has high surface active area and high graphitizing degree, is capable of increasing current intensity when the catalyst engages in catalytic reaction, and has excellent electrocatalytic activity and fast dynamical progress.

The present invention relates to a method for forming metal-silicide catalyst nanoparticles with controllable diameter. The method according to embodiments of the invention leads to the formation of ‘active’ metal-suicide catalyst nanoparticles, with which is meant that they are suitable to be used as a catalyst in carbon nanotube growth. The nano-particles are formed on the surface of a substrate or in case the substrate is a porous substrate within the surface of the inner pores of a substrate. The metal-silicide nanoparticles can be Co-silicide, Ni-silicide or Fe-silicide particles. The present invention relates also to a method to form carbon nanotubes (CNT) on metal-silicide nanoparticles, the metal-silicide containing particles hereby acting as catalyst during the growth process, e.g. during the chemical vapour deposition (CVD) process. Starting from very defined metal-containing nanoparticles as catalysts, the diameter of grown CNT can be well controlled and a homogeneous set of CNT will be obtained.

The invention discloses a new method for synthesizing patterned single-crystal tungsten oxide nanowire arrays with a catalyst localization technology. Employing a tungsten film as a source material and a metal nanoparticle film as a catalyst, the method comprises: (a) catalyst film localization synthesis: realizing film patterning through fixation of a ceramic template and a substrate material together or application of the exposure technology in a micromachining process, then enabling localization growth of the catalyst nanoparticle film in a vacuum plating instrument; (b) chemical vapor deposition: in a reaction gas atmosphere and at a temperature of 400-800DEG C, placing a W film into a CVD device for growth of 1-8h, then opening a fixation device or removing a photoresist, thus finally obtaining patterned tungsten oxide nanowire arrays. The preparation method of the invention not only can prepare patterned tungsten oxide nanowire arrays of different growth density, but also has the advantages of low reaction temperature (lower than 500DEG C) and suitability for the growth of low-melting point substrates.

A method for forming catalyst nanoparticles on a substrate and a method for forming elongate nanostructures on a substrate using the nanoparticles as a catalyst are provided. The methods may advantageously be used in, for example, semiconductor processing. The methods are scalable and fully compatible with existing semiconductor processing technology. Furthermore, the methods allow forming catalyst particles and elongate nanostructures at predetermined locations on a substrate.

The invention relates a method for synthesizing carbon nanofibers containing catalytic material particles characterized in that it comprises the following steps:

• a) electrospinning a polymer solution and a catalytic material precursor for obtaining polymer fibers containing catalytic material precursor particles,
• b) reducing the product obtained in a) with a reducing agent to form polymer fibers containing catalytic material particles,
• c) heat treating the product obtained in b) for converting the polymer fibers containing catalytic material particles into carbon fibers containing catalytic material particles.

The invention also relates to the intermediate products and products obtained by this method and use of these in various applications.

A catalyst manufacturing process includes heat treating an intermediate catalyst composition that includes catalyst nanoparticles having catalyst atoms in a non-zero oxidation state bonded to a dispersing/anchoring agent. The catalyst nanoparticles are formed using a dispersing agent having at least one functional group selected from the group of a hydroxyl, a carboxyl, a carbonyl, an amide, an amine, a thiol, a sulfonic acid, sulfonyl halide, an acyl halide, an organometallic complex, and combinations of these. The dispersing agent can be used to form single- or multicomponent supported nanocatalysts. The dispersing agent also acts as an anchoring agent to firmly bond the nanocatalyst to a support. Performing the heat treating process in an inert or oxidative environment to maintain the catalyst atoms in a non-zero oxidation helps maintains a stronger bonding interaction between the dispersing agent and the catalyst atoms. This, in turn, increases the dispersion and/or distribution of catalyst components throughout the supported catalyst.

A method of forming a hydrocarbon product comprises reacting at least one carbon oxide and at least one lower hydrocarbon in the presence of a plurality of catalyst-containing structures each comprising a nanofiber bound to at least one catalyst nanoparticle to form at least one higher hydrocarbon. Other methods of forming a hydrocarbon are also disclosed, as is a system forming a hydrocarbon product.

Nanoparticle catalysts are manufactured by first preparing a solution of a solvent and a plurality of complexed catalyst atoms. Each of the complexed catalyst atoms has at least three organic ligands. The complexed catalyst atoms are reduced to form a plurality of nanoparticles. During formation of the nanoparticles, the organic ligands provide spacing between the catalyst atoms via steric hindrances and/or provide interactions with a support material. The spacing and interactions with the support material allow formation of small, stable, and uniform nanoparticles. The supported nanoparticle catalyst is then incorporated into a fuel cell electrode.

A method of manufacturing nanofilter media includes feeding catalyst nanoparticles into a reactor to attach the catalyst nanoparticles to microfilter media located in the reactor and serving as a substrate; feeding a source gas and a reactive gas onto the catalyst nanoparticles; and heating the reactor to synthesize and grow, in the reactor, from the catalyst nanoparticles, any of nanotubes and nanofibers, to obtain a nanofilter media composed of the nanotubes or nanofibers.

A layer of high aspect ratio nanoparticles is disposed on a surface of a substrate under the influence of an electrical field applied on the substrate. To create the electrical field, a voltage is applied between a pair of electrodes arranged near the substrate or on the substrate, and the high aspect ratio nanoparticles disposed on the substrate are at least partially aligned along direction(s) of the applied electrical field. The high aspect ratio nanoparticles are grown from catalyst nanoparticles in an aerosol, and the aerosol is directly used for forming the nanoparticle layer on the substrate at room temperature. The nanoparticles may be carbon nanotubes, in particular single wall carbon nanotubes. The substrate with the layer of aligned high aspect ratio nanoparticles disposed thereon can be used for fabricating nanoelectronic devices.