Showing papers on "Noble metal published in 1983"

Ternary fuel cell catalysts containing platinum, cobalt and chromium

Abstract: An improved ternary noble metal-containing, alloy catalyst which has a catalytic activity for the electrochemical reduction of oxygen greater than two and one-half times that of the supported unalloyed noble metal alone. In addition, a disclosure of the method of preparing said catalyst is by intimately contacting two metallic elements with a supported noble metal, then heating this material to form the ternary alloy catalyst. This catalyst has particular utility for the electrochemical reduction of oxygen which makes it particularly useful as a cathode in acid fuel cells. The preferred embodiment of this catalyst is finely divided platinum alloyed with chromium and cobalt supported on an electrically conductive carbon-black support material.

Photodecomposition of Liquid Water with TiO2‐Supported Noble Metal Clusters

Abstract: Rh- and Ru-loaded TiO2-particles were produced from cluster precursors (Rh6(CO)16, Ru3(CO)12) and their activity in mediating H2O-decomposition through band-gap excitation was investigated. Activity increases in the order Ru

Hydrocracking of polyols

Abstract: Polyols such as carbohydrates including glucose, fructose, sorbitol, etc. may be subjected to a hydrocracking process to obtain lower polyols such as glycerol, ethylene glycol, 1,2-propanediol. The catalyst system which is used to effect this reaction will comprise a noble metal of Group VIII of the Periodic Table composited on a solid support plus an alkaline earth metal oxide, an example of this catalyst system being ruthenium composited on a titanited alumina support plus barium oxide.

Neutron activation determination of noble metals in rocks: A rapid radiochemical separation based on tellurium coprecipitation

Abstract: A procedure is described for the determination of Pd, Au, Ir, and Pt in rocks at the ppb concentration level. After irradiation with thermal neutrons, powdered rock samples are fused with carriers and Na2O2−NaOH. The fusion cake is dissolved in dilute HCl, and the activated noble metals and carriers are coprecipitated as a group with Te, using Sn2+ as a reductant. Gamma and X-rays are counted on semi-conductor Ge deterctors. Yields are determined by reirradiation. Results are given for several rocks, including U.S.G.S. standards PCC-1 and W-1.

Shielding material of electromagnetic waves

Abstract: The shielding material of electromagnetic waves of the invention is formedf a polymeric material as the matrix and an inorganic powder, e.g. mica flakes, metallized on the surface of the particles with a metal, e.g. nickel, as the conductive dispersant in the matrix. The metallization of the inorganic powder is performed by chemical plating, preferably, after pretreatment with an organic compound having a functional group capable of capturing ions of a noble metal and then with a solution containing a noble metal, preferably, palladium. This pretreatment is effective to increase the firmness of bonding between the metallizing layer and the surface of the particles so that the shielding effect of the material is greatly improved.

Doubly promoted platinum group metal catalysts for emission control

Abstract: Catalysts are made from supports which are doubly promoted with ceria and an alkali metal oxide by adding these promoters and the catalytic noble metal components in a specified order The ceria is first applied to the support It can be applied in a salt form such as cerous nitrate This impregnated support is then calcined to form a deposit of ceria Next, solutions bearing the noble metals are applied to the ceria-promoted support and with these solutions the alkali metal component is applied After subsequent elevated temperature activation, the alkali metal component is converted to an alkali metal oxide and the noble metals are converted into their metallic or oxide form When lithium is chosen as the alkali metal promoter, it can alternatively be applied to the support along with the initial ceria promoter After calcining the support to yield the ceria and lithia promoters, the noble metals can then be deposited and subsequently activated at an elevated temperature Using this process it is possible to have the noble metals deposited on the support so that their penetration depth is less than 300 microns as measured by the SnCl2 solution staining method to provide an effective three-way catalyst suitable for use in auto emission control

Process for the hydrogenation of aromatic hydrocarbons

Abstract: A process for the hydrogenation of aromatic hydrocarbons contained in a hydrocarbonaceous oil feed is provided in which the feed is contacted with hydrogen in a substantially sulfur-free environment in the presence of a catalyst comprising a Group VIII noble metal component, such as palladium, deposited on a steamed support such as steamed tungsten oxide composited with alumina.

Method for bonding ceramic to noble based metals and product

Abstract: A method of forming a clinically unbreakable composite structure between a noble based metal and a ceramic comprising depositing a thin layer of a bonding material including finely divided particles of a noble metal halide alone or in combination with particles of a noble metal; sintering the layer at a predetermined temperature between 1775° F. and 1975° F. and firing a ceramic over the sintered coating.

Schottky barrier formation and intermixing of noble metals on GaAs(110)

Abstract: Photoemission measurements are used to study the Schottky barrier formation and the intermixing (with GaAs) of the three metals, Cu, Ag, and Au, deposited at room temperature on GaAs(110) cleaved surfaces. It is tentatively concluded that Fermi level pinning cannot be followed satisfactorily for metal coverages above a monolayer. The work of Palau on Schottky barrier height (I–V and C–V) for Au and Ag deposited on cleaved GaAs(110) in UHV indicate pinning positions surprisingly close to those found for other overlayers in the ‘‘unified defect’’ model. It was found that ‘‘intermixing’’ between noble metals and GaAs decreases in the order of Cu, Au, and Ag. Although island formation probably occurs, it is tentatively concluded that the principle reason for difficulty in using our photoemission measurements to determine Efs for the noble metals is the inclusion of Ga (as well as As) in or on the noble metal overlayer.

Corrosion resistant aluminum electronic material

Abstract: A corrosion-resistant aluminum electronic material comprising an alloy containing aluminum as the principal component and, in addition, a small amount of a noble metal, the content of said noble metal being equal to or less than that at the eutectic point having the primary crystal of aluminum. As the noble metal, there is contained at least one metal selected from Pt, Pd, Rh, Ir, Os, Ru, Au and Ag. Said electronic material is used for ball-bonding wire and distributing film in a semiconductor device, and the like.

Reforming catalyst of methanol

Abstract: PURPOSE: To obtain a titled catalyst having high activity at low temp. and long life whereby H 2 and CO are produced selectively by depositing at least one kind of noble metal on the alumina carrier previously covered with oxide of alkali earth metallic element and oxide of rare earth element. CONSTITUTION: At least one kind of noble metal such as platinum and Pd is deposited on the alumina carrier previously covered with oxide of alkali earth metallic element and oxide of rare earth element. The amount of the oxides of said alkali earth metallic element and rare earth element covering this alumina carrier is preferably within the range of 0.05W50wt% respectively, and the deposited amount of at least one kind of noble metal such as platinum and Pd is preferably within the range of 0.01W10wt%. The catalyst obtained by said process is highly selective for the reaction wherein methanol is decomposed to the gas containing H 2 and CO, and is highly active and has extremely excellent durability. COPYRIGHT: (C)1985,JPO&Japio

Bound zeolite catalyst

Abstract: A class of bound catalysts which exhibit superior activity maintenance in dehydrocyclization reactions are defined as a type L zeolite having exchangeable cations of which at least 75% are selected from Group IA and calcium and barium cations and containing well dispersed particles of at least one Group VIII noble metal where at least 90% of the noble metal thereof is dispersed in the form of particles having a diameter less than 7 Å. The catalysts may also be identified as type L zeolites loaded with at least one Group VIII noble metal which have a terminal cracking index (as a measure of production of pentanes versus butanes from hexane) of at least 1.5.

Zeolite catalyst and preparation thereof

Abstract: A catalyst which exhibits superior activity maintenance in dehydrocyclization reactions are defined as a type L zeolite having exchangeable cations of which at least 75% are selected from Group IA and calcium and barium cations and containing well dispersed particles of at least one Group VII noble metal the preparation of which involves contacting the zeolite substantially free of moisture with a solution of the noble metal.

Preparation of catalyst for purifying exhaust gas

Abstract: PURPOSE:To develop a catalyst excellent in the removal effect of NOx, CH and CO in exhaust gas, by adhering a composition prepared by compounding a ceria powder with an activated alumina powder having Ce preliminarily contained therein to the surface of a monolithic carrier substrate before supporting a noble metal such as Pt, Rh or Pd. CONSTITUTION:A granular carrier comprising activated alumina such as gamma- alumina or delta-alumina immersed in an aqueous cerium nitrate solution and, after drying, the impregnated carrier is baked at 600 deg.C to prepare a carrier containing 1-5% of CeO2 as a metal. In the next step, an alumina sol and a ceria powder are mixed with the obtained powdery carrier in a predetermined ratio and crushed by a ball mill. In this case, the ceria powder is added to the alumina layer in a range of 5-50%. This alumina-containing solution is adhered to a monolithic carrier substrate and baked at 650 deg.C while the obtained baked one is allowed to support at least one noble metal such as Pt, Rh or Pd before baking. By this method, a catalyst excellent in the removal efficiency of NOx, HC and CO in the exhaust gas of an engine is obtained.

Single-batch process to prepare noble metal vanadium alloy catalyst on a carbon based support

Abstract: A novel single-batch method for preparing carbon supported alloy catalysts, wherein one of the metals is a noble metal, preferably platinum and the other metals selected from the transition Groups IV, V, VI or VII. The process comprises sequentially adsorbing the metallic components onto the carbon support. The adsorption takes place in an aqueous medium and the metal components are introduced in the ionic form. The catalyst is finally formed by heating to an elevated temperature.

In Situ Studies of the Electrode/Solution Interface by Photoacoustic Spectroscopy (PAS). PA Spectrum and Reflectivity of some Clean and Oxide-Covered Noble Metal Electrodes

Abstract: — 800 nm region have been measured of the following interfacial systems: Cu, Ag, Au, Pt, and thin transparent oxide-films on Cu, Au, and Pt, all of them in contact with aqueous electrolyte solutions and under well-defined electrochemical conditions. A method is given for the in situ calibration of the intensity of the spectra. Relations between the calibrated PA spectrum and the reflectance spectrum as well as between the DPA and the difference reflectance spectrum of the interfacial systems have been derived and examined. The comparison of the measured PA data and the reflectivity data of the systems either calculated from known values of the optical constants, n and k, or taken directly from the literature proves the complementary nature of PA and reflectance spectroscopies. Methodical aspects of both kinds of spectroscopy as applied to the study of the electrode/solution interface are discussed.

Process for the formylation of aryl halides

Abstract: Aryl halides are formylated with carbon monoxide and hydrogen in the presence of a noble metal catalyst, tertiary organic nitrogen compounds and phoshanes or phosphites.

Use of low-gold noble-metal alloys for dental purposes

Abstract: The alloys have good material bonding between the metal structure and the dental ceramic, have good processing properties, are not brittle at elevated temperature, do not discolour, in particular when the ceramic is fired, and in addition are inexpensive. Silver-containing alloys tend to discolour the ceramic; alloys containing a small amount of silver or none at all tend to be brittle at elevated temperatures. Surprisingly, it has been found that the disadvantages described do not occur if platinum and/or at least one of the transition metals from sub-group 4, 5 and 6 of the Periodic Table of the Elements are added to the low-gold noble-metal alloys.

Method of producing electrode for liquid fuel cell

Abstract: A method of producing an electrode useful as anode of a liquid fuel cell using methanol as fuel. The method has the steps of coating and impregnating a porous electrode body made of carbon with a noble metal such as platinum, activating the noble metal present on and in the electrode body and then depositing a base metal such as tin onto the surfaces of the electrode body coated with the activated noble metal for the purpose of maintaining the activated state of the noble metal coating. To rapidly accomplish the deposition of the base metal while the noble metal remains in the activated state, the method comprises an additional step of immersing the electrode body with the noble metal deposited thereon in a solution containing ions of the base metal precedent to the activation step. For the same purpose, it is very favorable to form through-holes in the electrode body for use in this method.

Thin film electroluminscent display device

Abstract: An improved dark field material for use in a thin film electroluminescent display device that typically includes a transparent electrode layer, a segmented electrode layer and an electroluminescent phosphor layer between the electrode layers. The improved dark field layer is of a composition of a dielectric material such as the preferred magnesium oxide and a noble metal, which is preferably gold co-evaporated by way of an electron beam deposition technique. The preferred range of noble metal by volume is 6%-10%. By varying the noble metal content within this range, there is provided control of the operating temperature of the electroluminescent display device.

Thin-film high pressure fuel cell

Abstract: A thin-film, high pressure fuel cell comprising at least one oxygen electrode and at least one hydrogen electrode separated by thin-film hydrophilic membranes wetted with a solution of electrolyte, each electrode comprising a hydrophobic porous membrane coated with a thin film of noble metal catalyst and having conducting elements associated therewith, said arrangement of electrodes, membranes and conducting elements being subjected to a gas pressure of 500 to 20,000 psi.

Solderable layer system, process for producing it and its use

Abstract: In order to be able to solder a conductive layer with an indium and/or tin oxide base, the following procedure is proposed: a noble metal is introduced into the surface of the conductive layer and nickel and/or copper are electrolessly deposited on the layer activated in this way. In order to promote the activation, the conductive layer is sensitised beforehand, i.e. it is provided with an agent which reduces noble-metal ions. The noble metal and reducing agent are preferably palladium and tin (II), respectively. Divalent tin is already present in an ITO layer, and this electrode is consequently already sensitised. The best results are obtained if the ITO layer is reactively sputtered on from an In/Sn/Pd target and then nickel-plated. The invention is primarily used in liquid-crystal displays with structurally integrated drive unit.

Preparation of carboxylic acids and esters thereof

Abstract: OF THE DISCLOSURE A carboxylic acid or an ester thereof having at least two carbon atoms more than formic acid is prepared by reacting at elevated temperature e.g. 100 to 250°C formic acid or a formate ester with an olefin e.g. ethylene in the presence of, as catalyst, a Group VIII noble metal e.g. iridium, preferably promoted by iodide, to cause addition of the formic acid or ester to the olefin and form the a higher acid e.g. propionic acid or ester thereof. A strong acid such as a sulphonic acid may be used as a copromoter. The catalyst is employed in solution.

Production of noble metal coated powder

Abstract: PURPOSE:To plate noble metals chemically and uniformly on the surfaces of a base material by mixing a powder base material with aq. gelatinous mixed solns. of noble metal compds., nonmetallic ammonium salts and aq. ammonia and adding a reducing agent to the mixed solns. under agitation. CONSTITUTION:Base powder of <=1mu grain sizes of transition metals of the 4th period of periodic table such as Cu, Ni, Co, Fe, or the like, or oxide type ceramics such as SiO2, ZrO2, Al2O3 or the like, or nonoxide type ceramics such as TiC, SiC or the like is added and dispersed to and in an aq. gelatinous soln. of 5-10pH contg. water-soluble metallic salts such as nitrate, chloride, cyanide and complex comps. of noble metals such as Ag, Au, Pd, Pt or the like, non-metallic ammonium salts such as NH4Cl and aq. ammonia. Hydrogenated Li-Al, hydrogenated B-Na or the like is added as a reducing agent for the noble metal compds. to said soln. under agitation. The noble metals are chemically plated to a uniform thickness on the surfaces of the base material powder without contamination by the base material.

Process for forming a catalyst and the catalytic product produced by the process

Abstract: A catalyst comprising a metallic carrier having a catalytically active metal-containing surface layer, the catalytic metal being other than a noble metal, wherein the catalytically active metal-containing surface layer is formed directly on the carrier by an etching treatment with an oxidizing inorganic acid which at least partially removes one or more metals from the surface of the metallic carrier, followed by chemical reduction with hydrogen.

Calibration of an X-ray photoelectron spectrometer by means of noble metals

Abstract: A review of the literature concerning binding energies of noble metal core levels has been carried out. From this data values for energy calibration in electron spectroscopy are recommended.