Journal Archive

Platinum Metals Rev., 1983, 27, (2), 96

NEW PATENTS: April 1983



METALS AND ALLOYS

High Chromium Superalloy

johnson matthey p.l.c. European Appl. 65,812

Alloys having good high temperature 1000−1100°C resistance to molten glass and good mechanical properties, for use in centrifugal spinners for glass fibre production, are Ni-Cr alloys having less than 25 vol.% of γ′ precipitate and containing up to 1.7% C, 0.3−4% Pt and/or Ru and up to 1.5% Ti and/or Al.

ELECTROCHEMISTRY

Electrochemical Cell

the electricity council British Appl. 2,098,238 A

The efficiency of an electrochemical cell having RuO2, Pt-Ir or platinised Ti electrodes is improved by positioning a turbulence promotor, such as a plastic mesh insert, in a flow path over one of the cell electrodes. The cell may be used for electrochemical reduction of oxidation.

Hydrogen Evolution Electrode

diamond shamrock corp. European Appls. 62,950/51

Cathodes for H2 evolution from aqueous electrolytes consist of a valve metal support coated with a catalyst finely dispersed in a matrix of semiconducting polymer. The polymer may be polyphenylene and the catalyst is a platinum group metal.

Hydrogen by Electrolysis

westinghouse electric corp. European Appl. 63,420

An electrolyser for the production of H2 from dilute H2SO4 saturated with SO2 consists of a series of half cells in which the anodes are preferably pellets of activated vegetable C mixed with 1−5% Pt powder.

Improved Anode for Halogen Production

general electric co. U.S. Patent 4,333,805

Cl2 or another halogen is produced electrolytically in a cell having a new catalytic anode consisting of 90% Ru oxide and 10% Mn oxide.

Ruthenium-Bipyridine Complexes in Water Photolysis

rikagaku kenkyusho U.S. Patent 4,338,291

Specified transition metal phthalocyanine complexes may be used to catalyse the production of H2 from protons and viologen cation radicals formed by the photolysis of water containing a viologen, EDTA and a Ru(bipy)3 complex.

Hydrogen Production

institute of gas technology U.S. Patent 4,341,608

In a process for liberating H2 by water electrolysis, the O2 produced simultaneously is used to oxidise a biomass of lignins and/or monosaccharides. The electrodes may be Pt, Pt-W, Pt-Ta or a Raney alloy.

ELECTRODEPOSITION AND SURFACE COATINGS

Palladium Electrodeposition

heraeus quarzschmelze g.m.b.h. U.S. Patent 4,339,311

Adherent, semiglossy to glossy, pore-free coatings are obtained by electrodeposition from Pd baths containing a specified amine but no NH3. A typical bath contains per litre, 10g Pd as K2[Pd(NO2)4], 60ml N–(2-aminoethyl)-1,3-diamino propane, 30g NaNO3 and 5g K citrate.

Platinum-Containing MCrAlY Coatings for Superalloys

united technologies corp. U.S. Patent 4,346,137

The addition of at least 13% of Pt and/or Rh to MCrAlY-type coating alloys brings the thermal expansion coefficient of the coatings closer to that of the superalloy substrate, and consequently improves the high temperature fatigue life of the coatings. The coating alloys, mainly for use on turbine blades, contain 8−30% Cr, 5−20% Al, 10−60% Ni, 8−30% Co, 0.005−1% of Y, Sc and/or La and a balance of Pt and/or Rh.

Rhodium Electroplating

degussa a.g. German Offen. 3,100,997

Fault-free bright Rh deposits of a white-gold colouration are obtained from baths containing Rh sulphate or phosphate, sulphuric and/or phosphoric acid and a sulphonic acid. A typical bath contains, per litre, 2g Rh as Rh sulphate, 40g H2SO4 and 0.5g of a 65% solution of phenolsulphonic acid.

Palladium-Nickel Electroplating

langbein-pfanhauser werke a.g. German Offens. 3,108,466/67

The quality of coatings formed by electrodeposition from a bath containing (per litre) 5−30g Pd and 5−30g Ni (as respective ammine complexes) and a carrier electrolyte, is improved by including an acetylenic alcohol amine in the solution.

LABORATORY APPARATUS AND TECHNIQUE

Determination of Anaesthetic Gas in a Carrier

dragerwerk a.g. British Appl. 2,098,741 A

Au electrodes and a Pt wire catalytic heater are used on a phthalocyanine detector for determining the amount of anaesthetic gas being fed to a patient.

Sensor for Monitoring the Heating Value of Fuel Gases

westinghouse electric corp. British Appl. 2,099,589 A

A fuel gas is sampled and the sample mixed with excess O2 and completely burned in a chamber, for example in the presence of a heated Pt sensing electrode which also acts as a catalyst. Either the O2 consumed or remaining after combustion is used as a measure of the heating value of the fuel gas.

Infrared Radiation Detector

commonwealth of australia European Appl. 60,854

A detector has a substrate covered with a detector element formed by an ultrathin i.r. absorbing film of Pd, Pt, Ir or Ni less than 10nm thick or a Au film less than 2onm thick.

Gas Sensors

siemens a.g. U.S. Patent 4,338,281

Thin film semiconductor gas sensors of Pt oxide or Pd oxide, for CO or hydrocarbons are provided with an integrated heating element. The connecting wires may be of Pt, Au, Ni or Al.

HETEROGENEOUS CATALYSIS

Pt-Re Catalyst for Aromatic Hydrocarbon Production

eif france British Appl. 2,096,481 A

An improved catalyst for the dehydrocyclisation of paraffins, especially useful for the production of light aromatics, contains 0.1−1.5% Pt, 0.1−1.5% Re incorporated into the support in the form of a carbonyl sublimed or dissolved in acetone and a small amount of S introduced as a H reducible or decomposable S compound supported on a zeolitic aluminosilicate.

Catalytic Combustion Engines

ricardo consulting engineers p.l.c. British Appl. 2,097,059 A

Each engine cylinder has a precombustion chamber communicating through a transfer passage to produce swirl around the chamber, and has a pair of parallel catalytic gauzes, for instance of Pt, mounted adjacent to both the mouth of the transfer passage and a fuel injector nozzle, so as to be clear of the swirl path of the gas circulating in the chamber. The injector injects a fuel spray between the catalytic gauzes so as to brush each screen and impinge on a heater plug. The system is used in diesel engines.

Fischer-Tropsch Catalyst

research association for petroleum alternatives development British Appl. 2,099,716 A

A catalyst giving high CO conversion in the production of hydrocarbons from synthesis gas consists of an Fe-based Fischer-Tropsch catalyst, a zeolite and Ru, Rh, Pd, Ir, Co and/or Mo.

Fuel and Air Injectors for Use in Gas Turbine Engines

rolls-royce ltd. British Appl. 2,100,852 A

A premixing system which thoroughly mixes fuel and air being injected into the combustion chamber of a gas turbine using catalytic ignition ensures lower pollution levels in the resulting exhaust gas. Catalytic ignition is carried out using Pt catalysts located in the combustion chamber.

Metal Fibre Catchment System

johnson matthey p.l.c. European Appl. 63,450

A getter pad for recovering Pt and Rh in nitric acid plants consists of an agglomeration of randomly orientated unwoven fibres of Ru, Pd, Ir, Pt, Au, Ag, Rh or an alloy of these metals. The pads, which are preferably of Pd or Au-Pd alloy, result in increased metal recovery and extended operating life over conventional woven getter pads.

Recombination Catalyst

varta batterie a.g. European Appl. 66,676

H2 and O2 produced in batteries are recombined on a catalytic unit. The unit consists of a web of PTFE and active C impregnated with Pd powder and hydrophobed with a PTFE suspension.

Catalyst Packing Module

atomic energy of canada ltd. European Appl. 68,862

A specified honeycomb catalyst packing module is designed to increase the vapour-liquid transfer rate in the isotopic exchange reaction between H2 and H2O. The active catalyst is a stainless steel gauze coated with a mixture of PTFE and platinised C powder.

Hydrocarbon Processing Catalyst

u.o.p. inc. U.S. Patent 4,337,146

The conversion of paraffins to aromatic hydrocarbons is catalysed by a mixture of 0.01−2% platinum group metal, 0.01−5% Re, 0.005−5% Fe and 0.1−3.5% Cl supported on a refractory oxide carrier, preferably Al2O3.

Catalyst Fabrication

johnson matthey inc. U.S. Patent 4,340,505

The amount of noble metal used in coating the exterior of a cylindrical catalytic device having a precoated honeycomb interior is reduced by protecting the ends of the device with a reusable impermeable jacket fixed with a Velcro fastening.

Catalysts for Paraffin Dehydrogenation

u.o.p. inc. U.S. Patent 4,341,664

The dehydrogenation of paraffins to olefins is catalysed by a composition consisting of a carrier such as Al2O3 supporting 0.05−1% platinum group metal, 0.01−1% Ag, 0.05−1% Re (deposited from a carbonyl complex) and 0.25−3.5% Group IA or IIA metal.

Alkali-Doped Heterogeneous Group VIII Metal Catalysts

allied corp. U.S. Patent 4,346,240

A new class of heterogeneous catalysts, useful in the hydrogenation of carboxylic acid esters to primary alcohols, contains platinum group metals in combination with Group IA organic compounds on a C support. Typical catalysts are K naphthalene and Ru/C and K benzphenone and Rh/C.

Selective Hydrogenation of Hydrocarbon Fractions

institut francais du petrole U.S. Patent 4,347,392

A Pd catalyst, having Pd crystallites of average size of at least 50Å supported on Al2O3, is selective for hydrogenating impurities in an ethylene and/or propylene cut. A suitable catalyst may be obtained by calcining an impregnated support at relatively high temperature in air and then subjecting the calcined catalyst to reductive treatment with H2.

Iridium-Ruthenium Catalyst for Hydrazine Decomposition

united technologies corp. U.S. Patent 4,348,303

A multistart catalyst which will initiate the thermal decomposition of hydrazine-base monopropellants used in rocket motors, even after the initial fuel flow has been terminated and the decomposition temperature has fallen, has 0.5−8% of Ir and/or Ru deposited on a high area ceramic carrier. The precious metal composition, deposited on the carrier is used with other catalysts, such as Mo and Co.

Separately-Supported Polymetallic Reforming Catalyst

mobil oil corp. U.S. Patent 4,349,433

Improved conversion rates in naphtha reforming are obtained by using two separately supported catalyst components. The first catalyst contains 0.1−5% Pt and 0.1−5% Re on a refractory support and the second 0.1−5% Ir and 0.1−5% of a halogen component on another refractory support.

Photodecomposition Catalysts

centre national de la recherche scientifique French Appl. 2,493,181

The photodecomposition of H2O is catalysed by a platinum group metal or Re supported on Sr titanate.

HOMOGENEOUS CATALYSIS

Alcohol, Carboxylic Acid and Ester Production

university of sheffield British Appl. 2,101,128 A

An alcohol and a compound containing a carboxylate group are produced from aldehydes or an aldehyde and a ketone by disproportionation in the presence of a noble metal complex catalyst, such as Rh2(C5Me5)2(OH)3Cl.4H2O.

Organic Platinum Group Metal Catalysts

minnesota mng. & mfg. co. European Appl. 61,241

New catalysts for hydrosilation reactions, especially for elastomer curing, contain Pt, Rh and Ir in a variety of complexes containing heterocyclic and especially phenazine molecules, such as (phenazine)PtCl2(C2H4), (imidazole)RhCl(CO)2 and (quinoxaline)RhCl(C8H12).

Very Large Transition Metal Clusters

wacker-chemie g.m.b.h. European Appl. 66,287

Highly active catalysts are clusters of formula M55L12Xp where M is a Group I, V, VI, VII or VIII metal, L is an electron donor, X is halogen and p is 6–20. They may be produced from LnMXm(n = 1−5, M = 1−6) and an Al hydride or B hydride reducing agent. One complex is Au55(PPh3)12Cl6 and similar Pt and Pd complexes are described.

Ruthenium Catalyst for Alcohol Production

union carbide corp. European Appl. 68,498

Methanol, ethanol and ethylene glycol are produced by the direct reaction of H2 and CO in the presence of a Ru carbonyl complex catalyst characterised by three i.r. absorption bands. I2 or an iodide must be present and the active catalyst is said to be a synergistic mixture of Ru(CO)3I3 and HRu3(CO)11.

Carboxylic Acid Homologation Catalyst

texaco inc. U.S. Patent 4,334,094

A system for catalysing the homologation of aliphatic carboxylic acids with synthesis gas contains Pd acetate, triphenylphosphine and CH3I.

Rhodium Cluster Complex Catalyst

snamprogetti s.p.a. U.S. Patent 4,334,101

A hydroformylation catalyst is obtained by exchanging a zeolite with {Rh(NH3)6}Cl3 and reacting the intermediate with H2 and CO to form a trapped carbonyl cluster complex.

Catalyst for Ethanol Production

gulf research and development co. U.S. Patent 4,346,020

A catalyst, effective for converting methanol, H2 and CO to ethanol, consists of a Co carbonyl or hydrido component, a tertiary organic phosphine or arsine component, an I compound and a Ru compound, such as Ru acetylacetonate.

Doped Acetylene Polymer

japan synthetic rubber co. ltd. U.S. Patent 4,349,664

Doped polymers having stable electrical properties are obtained by immersing an acetylene polymer in an organic solvent solution containing a dopant selected from platinum group metal complexes, carbonium salts, oxonium salts and parabenzoquinone derivatives. Typical dopants are (PhCN)2PdCl2 and (COD)PtCl3. The polymers are used in solar cells.

FUEL CELLS

Electrode Catalyst for a Fuel Cell

hitachi ltd. British Appl. 2,095,025 A

The use of a Pt-Ru heavy metal catalyst, such as Pt-Ru-Re and Pt-Ru-Sn, in acid electrolyte fuel cells which are driven by methanol, ethanol, etc., overcomes passivation problems experienced when Pt electrode catalysts are used.

Fuel Cell Construction

hitachi ltd. European Appl. 60,560

A fuel cell has a pair of gas diffusion electrodes sandwiching a metal oxide matrix which retains the phosphoric acid electrolyte. The matrix may be made of zirconia, SiO2, etc., and the gas diffusion electrodes of Pt/C powder.

Internal Reforming System for a Fuel Cell

energy research corp. European Appl. 67,423

A catalyst for reforming the hydrocarbon fuel of a fuel cell is located either on or adjacent to a plate or diffusion membrane which produces a differential pressure within the cell. In one form a diffusion plate for the reformed gas is located downstream of the catalyst. This may be of a Ni-Pd alloy which is porous to H2 gas.

Electrode System for Fuel and Electrolysis Cells

licentia patent-verwaltungs g.m.b.h. U.S. Patent 4,344,832

The facing sides of two plate electrodes have parallel grooves which, when brought into contact with an intervening membrane, form gas channels. The surface of the plates may carry catalyst layers and a wicking arrangement. Ni fuel cell plates have a Pt-catalyst layer on the cathode side and a Pt-Pd-catalyst layer on the anode side.

GLASS TECHNOLOGY

Transparent-Opal Glass

corning glass works U.S. Patent 4,336,303

In a process for obtaining colours in specified integral transparent-opal glass articles, a minute amount of a noble metal such as Pt, Rh, Ru, Au or Ag may be used as a coupling agent for TiO2.

ELECTRICAL AND ELECTRONIC ENGINEERING

Photoconductive Substrate

canon k.k. British Appls. 2,095,030/31 A

Pt, Pd, Au and base metal may be used as a support layer for photoconductive amorphous Si material having varying O atoms. The photoconductive layer is mainly for use in solar cells.

Refractory Metal Layers on Ceramics

international business machines corp. European Appl. 61,010

Conductive metal layers on ceramics which are free from glass are obtained by applying a refractory metal layer, such as a Mo paste, and then with a thin layer of Pd. On sintering the fusion of the refractory metal is catalysed by Pd and a compact layer is formed which excludes virtually any glass.

Resistive Pastes

n.v. philips' gloeilampenfabrieken European Appl. 67,474

A Ag-Pd resistive paste, which may be used in silk screening processes, contains an oxidic material based on Pd oxide together with a second oxide material to give improved temperature coefficients of resistivity. In preferred forms Ag-Pd alloy particles carry a coating of PdRhO2 or an oxide having the formula AgxPd1−xRhO2 is incorporated in the resistor material.

Heterojunction Semiconductor Device

hitachi ltd. European Appl. 67,721

A device is made from two layers of semiconductor, Si, one with impurity and the other without, whose interface forms the hetero junction. Pt may be deposited to form a Schottky gate, and Au employed in ohmic contacts.

Photoelectric Conversion Layer

hitachi ltd. European Appl. 67,722

A H2-containing amorphous Si layer is formed with specified temperatures in a plasma atmosphere. The layer may be improved by a semitransparent film of Pt, Pd or Au.

Magnetic Recording Medium

international business machines corp. European Appl. 68,131

The medium is a sputtered polycrystalline film of composition CoxPty where Co is 90 at.% or less of the material and Pt is 10−30 at.% of the material.

Gold Contact Surfaces

bell telephone laboratories inc. U.S. Patent 4,337,133

Durable, hard surfaces for electric contacts are made by sputtering Au together with a small amount of a refractory metal such as Ru, Os, Ir, Re or preferably Rh on to the contact surface.

Preparation of FETS

fujitsu ltd. U.S. Patent 4,343,657

Pd2Si and Pt2Si5 source and drain electrodes may be used on a FET device which is prepared by a method which includes direct selective nitridation followed by selective oxidation of the semiconductor substrate.

Platinum Cathode for a Gas Laser

ferranti ltd. U.S. Patent 4,344,905

Sputtering at the cathode electrode of a gas laser is considerably reduced if the cathode is made from a Pt pellet obtained by compressing Pt black powder under high pressure.

TEMPERATURE MEASUREMENT

Glass Coated Disc Thermistor

yellow springs instrument co. inc. European Appl. 61,550

A tri-metal contact film of Pt, Pd and Ag is metallurgically bonded to opposite surfaces of the resistance thermistor disc. This enables the assembly to be encased in a conformal glass coating after Ag-clad wires have been attached.

Thin Film Resistor

kabushiki kaisha kirk European Appl. 63,264

In a Pt thin film resistance element for use in a temperature sensor or gas sensor, a thin metal film is formed on an insulating substrate, a kerf is formed in the film to increase its resistance, and a pair of lead wires are attached to the ends of the film. The film is Pt of thickness 0.01−0.1 ¼ m.

MEDICAL USES

Gas Determination in Blood

hoffmann-la roche inc. U.S. Patent 4,333,473

The cutaneous blood gas concentration is measured by a microcathode while simultaneously the blood gas availability is measured by a large capacity cathode, the two heated cathodes forming a single unit. Both may be made of Pd and used with a single Ag anode.

Cis-Dichlorodiammine Platinum

mpd technology corp. U.S. Patent 4,335,087

Cis-Pt(NH3)2Cl2 is obtained by adding solid KCl to an aqueous solution of [Pt(NH3)2(H2O)2] [NO2]2 at room temperature, heating to about 70°C and holding for about 1 hour, allowing to cool, with stirring, to room temperature and filtering immediately.

Dental Alloy

unitek corp. U.S. Patent 4,336,290

A lower-cost dental alloy which does not discolour porcelain contains 80−90% Pd, 5−15% In, 1−5% Ga, 0.1−0.5% Al, 0.1−0.5% Si and 0.01−1% of Ru or Os.

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