4302 results about "Metal catalyst" patented technology

A process for producing hollow, single-walled carbon nanotubes by catalytic decomposition of one or more gaseous carbon compounds by first forming a gas phase mixture carbon feed stock gas comprising one or more gaseous carbon compounds, each having one to six carbon atoms and only H, O, N, S or Cl as hetero atoms, optionally admixed with hydrogen, and a gas phase metal containing compound which is unstable under reaction conditions for said decomposition, and which forms a metal containing catalyst which acts as a decomposition catalyst under reaction conditions; and then conducting said decomposition reaction under decomposition reaction conditions, thereby producing said nanotubes.

Novel methods and apparati for continuous production of aligned carbon nanotubes are disclosed. In one aspect, the method comprises dispersion of a metal catalyst in a liquid hydrocarbon to form a feed solution, and volatilizing the feed solution in a reactor through which a substrate is continuously passed to allow growth of nanotubes thereon. In another aspect, the apparatus comprises a reactor, a tube-within-a-tube injector, and a conveyor belt for passing a substrate through the reactor. The present invention further discloses a method for restricting the external diameter of carbon nanotubes produced thereby comprising passing the feed solution through injector tubing of a specified diameter, followed by passing the feed solution through an inert, porous medium. The method and apparati of this invention provide a means for producing aligned carbon nanotubes of a particular external diameter which is suitable for large scale production in an industrial setting.

Apparatus and method for cleaning air. An air cleaner includes a housing that defines an airflow pathway and a catalytic reactor having a catalyst secured on a porous substrate that is disposed transverse to the airflow pathway. Preferably, the catalyst includes a light activated oxidizing photocatalyst or a thermally activated oxidizing catalyst. A photocatalytic reactor will include a light source directed at a light activated oxidizing photocatalyst, such as TiO₂ particles or a binary oxide particle species, which is disposed on the porous substrate. Most preferably, a metal catalyst is disposed on the photocatalyst particles at a concentration or loading between about 0.01 wt % and about 5 wt %. The air cleaner may further comprise an adsorption matrix upstream of the catalytic reactor, optionally in combination with a heater. A particulate filter and/or an electrostatic precipitator may also be disposed upstream of the adsorption matrix and the catalytic reactor.

Compounds and method of preparation of Si—X and Ge—X compounds (X═N, P, As and Sb) via dehydrogenative coupling between the corresponding unsubstituted silanes and amines (including ammonia) or phosphines catalyzed by metallic catalysts is described. This new approach is based on the catalytic dehydrogenative coupling of a Si—H and a X—H moiety to form a Si—X containing compound and hydrogen gas (X═N, P, As and Sb). The process can be catalyzed by transition metal heterogenous catalysts such as Ru(0) on carbon, Pd(0) on MgO) as well as transition metal organometallic complexes that act as homogeneous catalysts. The —Si—X products produced by dehydrogenative coupling are inherently halogen free. Said compounds can be useful for the deposition of thin films by chemical vapor deposition or atomic layer deposition of Si-containing films.

Disclosed is a process that relates to the recovery of a metal catalyst from an oxidizer purge stream produced in the synthesis of carboxylic acid, typically terephthalic acid. The process involves the addition of a wash solution to a high temperature molten dispersion to recover the metal catalyst and then subjecting an aqueous mixture or purified aqueous mixture so formed to a single stage extraction to remove organic impurities to produce an extract stream and a raffinate stream comprising the metal catalyst.

A capping film serving as an interconnect protective film formed on a surface of interconnect metal on a semiconductor substrate is formed after forming a catalyst layer for electroless plating under low oxygen concentration condition. A method for forming a capping film for protecting a surface of interconnect metal includes preparing a metal catalyst solution containing a metal element nobler than interconnect metal and having dissolved oxygen concentration of 7 ppm or less, bringing said metal catalyst solution into contact with a surface of interconnect metal to form a metal catalyst layer on the surface of the interconnect metal, and performing electroless plating to form a capping film on the surface of the interconnect metal.

Disclosed are methods of purifying mixtures comprising nanofibers and/or nanotubes and residual catalyst particles that are covered by outer layers of the nanotube or nanofiber material. The mixtures are exposed to electromagnetic radiation, which induces localized heating in the residual catalyst particles. The localized heating creates breaches in the outer layers. Thereafter, the residual catalyst particles may be removed under relatively mild conditions that do not significantly affect the structural integrity of the nanotubes or nanofibers. The methods of the invention have been used to particular advantage in the purification of single wall carbon nanotubes (SWNTs) synthesized using metal catalysts. For these SWNTs, microwave radiation is preferably used to induce the localized heating, the outer layers are preferably removed at least in part by carrying out the localized heating under air, and the residual catalyst may be removed by exposure to relatively dilute aqueous acid.

This invention provides an aligned single-layer carbon nanotube bulk structure, which comprises an assembly of a plurality of aligned single-layer carbon nanotube and has a height of not less than 10 μm, and an aligned single-layer carbon nanotube bulk structure which comprises an assembly of a plurality of aligned single-layer carbon nanotubes and has been patterned in a predetermined form. This structure is produced by chemical vapor deposition (CVD) of carbon nanotubes in the presence of a metal catalyst in a reaction atmosphere with an oxidizing agent, preferably water, added thereto. An aligned single-layer carbon nanotube bulk structure, which has realized high purify and significantly large scaled length or height, its production process and apparatus, and its applied products are provided.

Disclosed are oxygen-scavenging polymer compositions having high transparency and low haze comprising immiscible blends of at least one polyester comprising 2,2,4,4-tetramethyl-1,3-cyclobutanediol, a copolyamide or a transamidized, homogeneous blend of a least two polyamides, and a metal catalyst. The components of the immiscible blend which have refractive indices which differ by about 0.006 to about −0.0006. The small difference in the refractive indices enable the incorporation of regrind into the polymer composition to produce transparent shaped articles. The blends of the present invention are useful in producing shaped articles such as, for example, sheeting, films, tubes, bottles, preforms and profiles. These articles may have one or more layers and can exhibit improved excellent barrier properties and good melt processability while retaining excellent mechanical properties.

An improved vapor phase deposition method for preparation of single walled carbon nanotubes on an aerogel supported metal catalyst. The total yield of SWCNTs often is at least about 100%, based the weight of the catalyst, for a reaction time of at least about 30 minutes.

Provided is a method of producing FDCA by which high-purity FDCA can be produced in high yield. 2,5-furandicarboxylic acid is produced by: bringing 5-hydroxymethylfurfural into contact with an oxidant in an organic acid solvent in the presence of bromine and a metal catalyst; and allowing 5-hydroxymethylfurfural and the oxidant to react with each other while removing water produced by the reaction.

The present invention is to provide anode active material hybridized with carbon nano fibers for lithium secondary battery prepared by following steps comprising, i) dispersing the nano size metal catalyst to the surface of anode material selected from graphite, amorphous silicon or the complex of graphite and amorphous silicon; and ii) growing the carbon nano fiber by chemical vapor deposition method, wherein carbon nano fibers are grown in a vine form and surround the surface of anode active material.

Single-walled carbon nanotubes have been synthesized by the catalytic decomposition of both carbon monoxide and ethylene over a supported metal catalyst known to produce larger multi-walled nanotubes. Under certain conditions, there is no termination of nanotube growth, and production appears to be limited only by the diffusion of reactant gas through the product nanotube mat that covers the catalyst. The present invention concerns a catalyst-substrate system which promotes the growth of nanotubes that are predominantly single-walled tubes in a specific size range, rather than the large irregular-sized multi-walled carbon fibrils that are known to grow from supported catalysts. With development of the supported catalyst system to provide an effective means for production of single-wall nanotubes, and further development of the catalyst geometry to overcome the diffusion limitation, the present invention will allow bulk catalytic production of predominantly single-wall carbon nanotubes from metal catalysts located on a catalyst supporting surface.

An inexpensive, highly catalytic material preferably formed by a leaching process. The catalyst comprises a finely divided metal particulate and a support. The active material may be a nickel and/or nickel nickel alloy particulate having a particle size less than about 100 Angstroms. The support may be one or more metal oxides.

Thermal interfaces and methods include an array of carbon nanotubes aligned substantively perpendicularly from a substrate. One method includes arranging metal catalyst particles with a particular ligand on a fluid surface of a Langmuir-Blodgett trough. This forms uniformly spaced particles with spacing based on the particular ligand. The uniformly spaced metal catalyst particles are deposited on a substrate and carbon nanotubes are grown on the particles using chemical vapor deposition. A highly efficient thermal interface can be produced with a carbon nanotube packing ratio greater than fifty percent and used in a thermal switch or other device. In some methods, commercially available nanotubes are condensed on a substrate using carbon nanotubes with terminal carboxylic acids in solution and an amine monolayer on the substrate. Pretreatment of the nanotubes in a switch by applying heavy pressure between two surfaces results in good thermal conductivity between those surfaces at smaller operating pressures.

Disclosed is a process for the preparation of shaped articles such as, for example, sheeting, films, tubes, bottles, preforms and profiles, having high transparency and low haze, and comprising immiscible blends of at least one polyester comprising 2,2,4,4-tetramethyl-1,3-cyclobutanediol, and a copolyamide or a transamidized, homogeneous blend of a least two polyamides. The components of the immiscible blend have refractive indices which differ by about 0.006 to about −0.0006. The small difference in the refractive indices enable the incorporation of regrind into the polymer composition to produce transparent shaped articles. These articles may have one or more layers and can exhibit improved excellent barrier properties and good melt processability while retaining excellent mechanical properties. Metal catalysts can be incorporated into the compositions to produce shaped articles having oxygen-scavenging properties.

The invention discloses preparation methods for a macroporous alumina carrier and a hydrodemetallization catalyst. The preparation method for the macroporous alumina carrier includes the following steps: (1) dry pseudoboehmite gel powder is hydrothermally processed under high pressure; (2) the dry pseudoboehmite gel powder obtained in step 1 is kneaded into a plastic, and pore-expanding agent is added in step 1 or step 2; (3) the plastic obtained in step 2 is shaped, the shaped material is dried and baked, and thereby the macroporous alumina carrier is obtained. The impregnation method is adopted to prepare the hydrodemetallization catalyst. The hydrodemetallization catalyst prepared by the method has large pore volume and pore diameter, centrally distributed pores, moderate mechanical strength and high activity and activity stability.

Amongst the candidates for very high efficiency solid state lights sources and full solar spectrum solar cells are devices based upon InGaN nanowires. Additionally these nanowires typically require heterostructures, quantum dots, etc which all place requirements for these structures to be grown with relatively few defects. Further manufacturing requirements demand reproducible nanowire diameter, length etc to allow these nanowires to be embedded within device structures. Additionally flexibility according to the device design requires that the nanowire at the substrate may be either InN or GaN. According to the invention a method of growing relatively defect free nanowires and associated structures for group III—nitrides is presented without the requirement for foreign metal catalysts and overcoming the non-uniform growth of prior art non-catalyst growth techniques. The technique also allows for unique dot-within-a-dot nanowire structures.

A gas-phase method for producing high yields of single-wall carbon nanotubes with high purity and homogeneity is disclosed. The method involves using preformed metal catalyst clusters to initiate and grow single-wall carbon nanotubes. In one embodiment, multi-metallic catalyst precursors are used to facilitate the metal catalyst cluster formation. The catalyst clusters are grown to the desired size before mixing with a carbon-containing feedstock at a temperature and pressure sufficient to initiate and form single-wall carbon nanotubes. The method also involves using small fullerenes and preformed sections of single-wall carbon nanotubes, either derivatized or underivatized, as seed molecules for expediting the growth and increasing the yield of single-wall carbon nanotubes. The multi-metallic catalyst precursors and the seed molecules may be introduced into the reactor by means of a supercritical fluid. In addition the seed molecules may be introduced into the reactor via an aerosol or smoke.

The present invention relates to a pseudothin diaspore composition containing organic pore-expanding agent. Said composition contains 92-99.5 wt% of pseudothin diaspore and 0.5-8 wt% of organic pore-expanding agent, in which the crystallinity of pseudothin diaspore is 10-70%. In the pseudothin diaspore composition provided by said invention the organic pore-expanding agent content is low, after high-temperature calcination the alumina with large pore capacity and large pore diameter can be obtained. Said alumina can be used as carrier material for preparing hydrodemetalization catalyst for heavy oil, residual oil and short residuum specially.

The process of this invention is directed to the removal of metals from an unsupported spent catalyst. The catalyst is subjected to leaching reactions. Vanadium is removed as a precipitate, while a solution comprising molybdenum and nickel is subjected to further extraction steps for the removal of these metals. Molybdenum may alternately be removed through precipitation.