Journal Archive

Platinum Metals Rev., 1971, 15, (1), 35

NEW PATENTS: January 1971


Alloys of Variable Transition Temperature

f. e. wang & w. j. buehler British Patent 1,202,404

The alloy JLxMl−x has a martensitic transition temperature depending on the ratio L:M. J is a Group VIA metal, and makes up 50 at.% of the alloy, the remaining 50% being L+M, where x is greater than 0 and less than 1. Typically, J is Zr, L is Rh and M is Ru or J is Zr, L is Pd and M is Rh.

Workable Duplex Structured Ruthenium Alloys

international nickel co. inc. U.S. Patent 3,498,763

A cold-workable Ru alloy capable of being cold drawn to wire contains about 60−90% Ru, 5−40% Cu, up to about 35% Pd and up to 10% Ni. It is produced by liquid-phase sintering, preferably by infiltration of Cu or Cu alloy, into a Ru compact at a temperature between 1083°C and 1500°C.

Dispersion-hardened Noble Metals

p. r. mallory & co. inc. U.S. Patent 3,515,542

Cu, Au, Ag, Pt, Pd and their alloys are strengthened or hardened by introducing up to 10% of a compound of Cr, Ti, Th, U, Zr, B or Si or alloys thereof. A melt is formed of the noble metal and the hardening element and gas bubbled through the melt to form the compound, usually an oxide.

Hardening of Platinum Metals

johnson, matthey & co. ltd German Appl. 1,533,275

Pt, Pd, Rh and their alloys with one or more other Pt metals are hardened by the addition of a small amount of one or more base metals. These metals, such as Cr, must form compounds stable at high temperatures.

Dispersion-strengthened Metals

johnson, matthey & co. ltd German Appl. 1,935,329

A molten metal (Ag, Au or a Pt metal) is sprayed, together with a disperse-phase component (oxide, carbide, nitride, or sulphide) on to a cooled former. The product may be suitable for, e.g., electric contacts, thermoelements or resistors; or for use as a catalyst, diffusion membrane or spinneret.


Electrically Conductive Oxides Containing Palladium

e. i. du pont de nemours & co. U.S. Patent 3,498,931

New electrically conductive oxides have the formula PdMO2, in which M is Co, Cr, Rh or Cr/Rh, but may vary slightly in stoichiometry from the formula. They are prepared by the reaction of a Pd dihalide, optionally mixed with Pd, and an appropriate oxide containing M.

Organometallic Polymers

mcdonnell douglas corp. U.S. Patent 3,504,052

A novel class of polymers contains ruthenocene or osmocene units which are interlinked to form polymeric products having high heat stability and other advantageous properties. They are produced by reacting ruthenocene or osmocene with an aldehyde or ketone in the melt phase and in the presence of a Lewis acid catalyst.


Metallising of Ceramics

e. i. du pont de nemours & co. British Patent 1,202,999

A ceramic is metallised by applying to its surface a finely divided granular noble metal powder. This powder comprises at least 60 wt.% of Pt and optionally a further metal selected from Pd, Rh and/or Ru. At least 50 wt.% of the Pt must have a surface area of 0.01−1 m2/g. The coated surface is fired, preferably at 1400−2000°C, to give a tightly adherent conductive metal film.

Oxidation-resistant Coated Article Containing Iridium, Ruthenium, Molybdenum or Tungsten

international nickel co. inc. U.S. Patent 3,499,740

A coated metal article has a body and a coating of different compositions which are resistant to interdiffusion at elevated temperatures. They are single-phase conjugate compositions falling at opposite terminals of an alloy tie line on a ternary metallurgical system diagram having Au at one apex, Pd at a second; Ru, Ir, W or Mo at the third.

Palladium Coated Electric Contacts

international nickel co. inc. U.S. Patent 3,500,537

Corrosion-resistant electrical contacts are made coated with Pd. The Pd is electrodeposited from an aqueous ammoniacal bath comprising tetrammino-palladous bromide and having a pH of about 8–10. The deposit is highly ductile thus permitting deformation to form electrical contacts.

Plating Solutions for Rhodium

k. ohkubo et al. U.S. Patent 3,515,651

An electrolyte for electroplating low stress Rh and Rh alloy deposits comprises a Rh salt, optionally a salt of another metal capable of alloying with Rh and at least one of hexameta-phosphoric acid and alkali metal or ammonium hexametaphosphates.


Brazing Alloy for Joining Graphite to Graphite and to Refractory Metals

u.s. atomic energy commission U.S. Patent 3,497,332

The joining of graphite to graphite and to refractory metals such as Mo, W and their alloys is effected with a brazing alloy consisting essentially of Ni, Pd and 2−12% Cr.

Solderable Stainless Steel

p. r. mallory & co. inc. U.S. Patent 3,515,950

A method for rendering solderable a stainless steel body resistant to corrosive attack from common electrolytes includes covering one layer of a stainless steel body with layers of metal. A first metal layer serves as a barrier layer to the diffusion of a subsequent metal layer through to the stainless steel body. The subsequent metal layer is resistant to corrosive attack from common electrolytes, is solderable and consists of Ag alloyed with Au, Pd, Pt, Re or Os. The alloy layer may be formed by covering the barrier layer with a layer of Ag and Au or one of the other metals. The layered stainless steel body is heated to a temperature below the melting point temperature of the metal layer having the lowest melting point so that the layers (except the barrier layer) diffuse into one another, forming an alloy layer overlaying the barrier layer.

Solder for Thermoelements

siemens a.g. German Appl. 1,533,547

The solder is an alloy of composition:


where Me is Fe or a metal of Group IV, V or VI, other than Cr and Zr, and y is ≥0.

Soldering Semiconductors

telefunken patentverwertungs-g.m.b.h. German Appl. 1,564,901

A diode or transistor is attached to a Mo or W base by two layers of a noble metal, preferably Rh.

Solder for Steel and Refractory Alloys

l. a. markovich et al. U.S.S.R. Patent 261,887

The solder has the composition 32−34% Pd, 22−25% Ni, 11−13% Cr and the remainder Cu.


Self-cleaning Gas Ovens

general electric co. British Patent 1,200,087

Cooking fumes in a gas oven are oxidised by an oven liner coated with a Pt catalyst.

Dehydrogenation Catalyst

british petroleum co. ltd British Patent 1,200,651

Normal alkanes are dehydrogenated to normal alkenes in the presence of a Pt group metal exchanged on to a molecular sieve.

Oxidation Catalyst

instytut nawozow sztycznych British Patent 1,200,952

Concentrated NO is formed by the oxidation of NH3 with O2 and water vapour in the presence of a Pt catalyst.

Acrylonitrile Dimerisation Catalyst

e. i. du pont de nemours & co. British Patent 1,205,285

Adiponitrile is prepared by the dimerisation of acrylonitrile in the presence of a catalyst which is a mixture of a water-soluble salt of a carboxylic acid and a water-soluble Ru salt, supported on C or Al2O3.


imperial chemical industries ltd British Patent 1,205,521

Aromatic isocyanates are prepared by the action of nitro or nitroso compounds with CO in the presence of a catalyst which is a mixture of at least one of the noble metals Ru, Rh, Pd, Os, Ir and Pt with two or more heavy metal oxides, hydroxides, carbonates, basic carbonates or basic phosphates.

Isomerisation Catalyst

imperial chemical industries ltd British Patent 1,205,677

The isomerisation of olefines is effected in the presence of noble metals, preferably Pt, Ru or Pd. Pd gives best results.

Two-stage Hydrocarbon Hydrogenation

universal oil products co. U.S. Patent 3,494,859

An aromatic hydrocarbon feedstock containing diolefines, mono-olefines and sulphur contaminants is hydrogenated at a relatively low temperature of 200−500°F with a composite catalyst of Li in Pd (1)/Al2O3 to convert the diolefines to mono-olefines. Conventional desulphurisation is then carried out.

Production of Acrylonitrile and Methacrylonitrile

sun oil co. U.S. Patent 3,499,025

Acrylonitrile and methacrylonitrile are prepared by reacting C3H6 and iso -C4H8 respectively with air or O2 in the presence of a slight excess of NH3 over a Pt catalyst. The catalyst is in the form of a metallic gauze. Temperatures of from 750−1000°C and contact times of less than 0.1 second are used.

Hydrogenation of Aromatic Nitro Compound

e. i. du pont de nemours & co. U.S. Patent 3,499,034

A new process is described for the hydrogenation of aromatic nitro compounds. It is a continuous, one stage process producing a yield of about 99% of theory of substantially pure aromatic amine. Pd/C is a preferred catalyst.

Apparatus for Treating an Exhaust Gas Stream with Different Catalyst Beds

universal oil products co. U.S. Patent 3,503,715

A unitary apparatus for effecting the catalytic oxidation of engine exhaust gases, where there may be both high and low quantities of hydrocarbon emissions with such gases, has one catalyst layer comprising Pt/Al2O3 particles containing a Ba, Ca or Sr component.

Catalytic Reforming Process

universal oil products co. U.S. Patent 3,515,665

A continuous low pressure reforming process is described using a Pt catalyst.

Catalytic Hydrocarbon Conversion

british petroleum co. ltd U.S. Patent 3,516,925

A new conversion catalyst for waxy petroleum feedstocks consists of a Group VI or Group VIII metal deposited on a decationised mordenite containing up to 2% of non-catalytic metal cations. The mordenite must have pore openings of 5Å or more. A Pt catalyst deposited on decationised mordenite is described in several examples.

Naphtha Reforming Process

chevron research co. French Patent 1,583,982

Reforming with a Pt-Re supported catalyst is effected in specified process conditions.

Hydrogenation Catalyst

deutsche gold- und silber-scheideanstalt German Appl. 1,542,089

Liquid-phase hydrogenation can be achieved at comparatively low temperatures and pressures in the presence of a Pt group metal catalyst in suspension, e.g. finely divided Pd.


johnson matthey & co. ltd German Appl. 1,542,214

Catalysts which are active in oxidation, reduction, hydrogenation and dehydrogenation reactions consist of homogeneous mixtures of two or more noble metal (except Os) oxides. They are not just physical mixtures but are formed, e.g. by co-precipitation from a mixed salt solution.


johnson matthey & co. ltd German Appl. 1,542,216

A catalyst which is useful for, e.g. oxidation and hydrogenation reactions, consists of a coprecipitated mixture of Pt and Ru oxides, with the weight ratio of the two metals being approximately: Pt from 20 to almost 90; Ru from just over 10 to 80.


johnson matthey & co. ltd German Appl. 1,542,239

A catalyst which is active in oxidation and reduction reactions, for example, consists of a mixture, in the proportions of at least 3 : 1, of a noble metal oxide (excluding oxides of Os) with at least one oxide of Fe, Co, Ni or Cu.

Reduction Catalyst

inventa a.g. fur forschung und patent-verwertung German Appl. 1,567,596

NO may be reacted with hydrogen in H2SO4, in the presence of a Pt catalyst (e.g., 2% Pt/C), to give hydroxylamine sulphate.

Oxidation Catalyst

celanese corp. German Appl. 1,568,364

The partial oxidation of organic compounds, e.g., alcohols, aldehydes, ketones, by an alkali metal or alkaline earth metal hypochlorite is catalysed by the presence of Ru.

Reforming Catalyst

chevron research co. German Appl. 1,932,339

The catalyst consists of a porous inorganic oxide combined with 0.01−3 wt.% of Pt, 0.01−5 wt.% of Re and 0.1−3 wt.% of a halide.

Hydrocracking Catalyst

chevron research co. German Appl. 1,947,979

The catalyst is a crystalline zeolite molecular sieve supporting 0.01 to 2.0 wt.% of Pt, Pd or Ir and 0.01 to 2.0 wt.% Re or their compounds.

Vinyl Acetate Production

knapsack a.g. Dutch Appl. 69.15,305

Vinyl acetate and other esters are produced from olefines, acids and O2 by passage over a catalyst comprising supported Pt metal. The support, e.g. SiO2, has a particle size of 0.1−1.5 mm, preferably 0.1−0.5 mm. It may be hollow.


OXO Catalyst

mitsubishi chemical industries ltd British Patent 1,202,507

The reaction between an olefinic compound, CO and H2 can be carried out continuously in the presence of a solution of a Rh compound in a polar organic solvent, e.g. Rh nitrate, acetate or chloride in methanol.

Polymerisation Catalysts

celanese corp. British Patent 1,202,681

The polymerisation of oxymethylene and/or thiomethylene units is catalysed by hydrated trihalides of Ru, Rh, Pd, Cs, Ir and Pt.

OXO Catalyst

british petroleum co. ltd British Patent 1,202,779

Olefines are conveniently hydroformylated in the presence of a catalyst which is a complex of Ir with one carbonyl ligand, one hydride ligand and three other neutral ligands. A typical Ir complex is IrHCO(Ph3P)3.

Oxidation Catalysts

british petroleum co. ltd British Patent 1,206,166

Olefines are oxidised by an O2-containing gas in the presence of a complex of a Group VIII metal, especially Ir(PPh3)2COCl, Rh(PPh3)3I and Rh(PPh3)3Cl.

Rhodium Complex Carbonylation Catalysts

ethyl corp. U.S. Patent 3,515,757

Aldehydes are produced from olefines, CO and H2 using a complex of formula RhHX2(CO) (TL3)2, where X is halogen (except F), L is the same or different H atom, 6–12 C aryl, 7–12 C alkaryl or 1–12 C alkyl group, and T is P, As or Sb. Typical catalysts are Rh hydridocarbonylbis(triphenyl arsine) dichloride and Rh hydrido-carbonylbis(n-heptyldi-β-naphthylphosphine) dibromide.

Hydroquinone Production

lonza s.a. French Patent 2,014,219

Hydroquinone is produced from C2H2, CO and H2 in the presence of a trimeric Ru tetracarbonyl.

Hydrogenation Catalyst

e. i. du pont de nemours & co. German Appl. 1,542,380

The catalyst is made by mixing and heating together finely-divided Al2O3, Ru chloride or nitrosonitrate and (NH4)2CO3 or bicarbonate.

Hydrogenation Catalysts

imperial chemical industries ltd German Appl. 1,568,817

Olefinic and acetylenic compounds are hydro-genated in the presence of specified Rh complexes, especially RhX(Ph3P)3, where X is an anionic group such as halide.

Hydroformylation Catalyst

johnson matthey & co. ltd. German Appl. 1,939,322

A catalyst for hydroformylation is a Rh hydrido-carbonyl phosphine complex, e.g. RhH(CO) (PPh3)3.


Fuel Cell

united aircraft corp. British Patent 1,200,022

In a fuel cell system capable of operating at full load in the temperature range −40° to +50°C, the catalyst is Pt black.

Fuel Cells

general electric co. British Patent 1,204,540

In such a cell the fuel electrode consists of a support material of a metal silicide, Ta boride, Ti boride or B carbide on which is dispersed a catalyst. The latter consists of a Pt-Ru alloy containing 20 to 80 wt.% of Ru.

Palladium Hydrogen Diffusion Fuel Cell Electrode

u.s. secretary of the air force U.S. Patent 3,497,390

A fuel cell has an electrolyte positioned in a container between a porous oxygen electrode to which oxygen is supplied and a non-porous Pd anode to which gaseous H2 is supplied. The Pd anode is produced by heating a Pd strip in air to a temperature between 500°C and 875°C.

Fuel Cell Cathode

leesona corp. U.S. Patent 3,514,336

A fuel cell cathode is a lightweight structure consisting of a mixture of Pt black or another catalytic metal and a hydrophobic polymer such as ptfe.


Hydrogen Release for a Heat Pipe

a.c.f. industries inc. U.S. Patent 3,503,438

A heat pipe system, particularly for a railway car, using water which may dissociate and develop a dangerously high pressure of H2, is provided with a H2 release device located outside the car. The release device is a Pd or Pd alloy tube sealed to a wall of the heat pipe system and having a closed inner end and an open outer end.

Dispersion-strengthened Metals

johnson matthey & co. ltd French Patent 2,012,909

A mixture of a “host” metal (e.g. a Group VIII noble metal) and a smaller proportion of at least one more reactive metal, in the form of a powder, is projected at high temperature through an atmosphere which will react with the more reactive metal (to form, e.g. oxide, sulphide, nitride), and collected on a cooled surface.


Method of Forming Jets in Bushing Baseplates

owens-corning fiberglass corp. U.S. Patent 3,514,841

A method of forming jets in bushing base-plates made of Pt or Pt alloy is described. Pt-Rh and Pt-Ir containing from 1−10 wt.% of gold (especially 2−6% Au) are preferred. The metal is formed into a body having solid raised portions on one surface, further metal is joined to each of these portions and passage ways are formed through them by the application of dies under pressure. Further metal joined may be of a different alloy.


Electrical Heaters for Glass

triplex safety glass co. ltd British Patent 1,202,522

An “ink” containing metal particles or a chemical which will produce such particles on firing, is applied to the glass by silk-screen printing. The metal may be Ag, Au, Pt or Pd.


imperial chemical industries ltd British Patent 1,206,863

Electrodes, e.g., for the electrolysis of alkali metal chlorides, are obtained by coating Ti with an operative electrode material. This consists of oxides of at least one Pt group metal or mixtures thereof with at least one Pt group metal. The preferred composition is RuO2.

Alloy for Electrical Leads

wilkinson dental manufacturing co. inc. U.S. Patent 3,495,978

A new alloy for electrical leads normally embedded in a ceramic base constituting a portion of an electrical component, such as a potentiometer, is described. The alloy consists of from 64−90% Au, 10−35% Pd and 0.5−2% Ru. The proportions are selected so that a greatly improved lead wire is provided in which oxidation is substantially avoided even at the firing temperatures of the ceramic base in which the lead is embedded.

Metallising Ceramics

e. i. du pont de nemours & co. U.S. Patent 3,497,384

A process for metallising a ceramic substrate by applying a noble metal powder consisting of 60−100% Pt (having a surface area within the range of 0.1−1 m2/g) and optionally Pd, Rh, Ru and their alloys or mixtures and firing the powder at a temperature within the range of 1400−2000°C is described. The metal powder forms a tightly adherent conductive metal coating on the ceramic substrate. The process does not use the conventional inorganic binders.

Manufacture of Electrodes

nippon carbide k.k. U.S. Patent 3,497,426

Electrodes are made by mechanically cleaning a Ti surface in the absence of O2 or N2 (e.g., by buffing with sandpaper in benzene). They are immediately transferred to a vacuum container, avoiding contact with O2 or N2, and a first Pt group metal coat is then vapour plated on to the cleaned surface to a thickness of 100−3000 Å. A second coating of Pt or Rh is subsequently electroplated on to the surface to a thickness of 0.1−5 μ. The electrode is suitable for the electrolysis of chlorides and sulphates.

Tungsten Dispenser Cathode

u.s. philips corp. U.S. Patent 3,497,757

An improved coated dispenser-type cathode consisting of a metal matrix of W or W-Mo in reactive relationship with an alkaline earth metal compound which will supply Ba or BaO to the emitting surface of the matrix is described. The matrix emitting surface is coated with a thin porous layer of an alloy of Os and Ir, or Os and Ru, to provide longer cathode lifetime. There is also less danger during the manufacture of the cathode than with prior art coated cathodes.

Electrically Conducting Platinum Cobalt Oxides

e. i. du pont de nemours & co. U.S. Patent 3,514,414

An electrically conductive PtCo oxide is described having the formula PtxCoyO2, where x and y are 0.85±0.15, and a crystal structure based on the rhombohedral space group R3m. It is prepared at elevated temperature and pressure from Co3O4 and PtO2. The compound, which may be slightly modified with Mn, is useful in electrical resistors.

Current Collectors for Cells with Hot Acid Electrolytes

general electric co. U.S. Patent 3,515,595

Current collectors comprise ternary alloys consisting of Ni, Pd and Au. For cells using a hot phosphoric acid electrolyte the alloy preferably consists of 50−80% Ni, 5% Pd and 2% Au on a weight basis. For cells using hot H2SO4 or sulphonic acid polymer electrolyte the alloy preferably consists of 30−50% Ni, at least 30% Pd and at least 5% Au, on a weight basis.


produits chimiques pechiney-st. gobain French Patent 1,586,120

Electrodes, particularly anodes for the electrolysis of alkali metal chlorides, consist of Ti coated with a noble metal, e.g., Pt.

Electric Resistor

johnson matthey & co. ltd German Appl. 1,640,561

The resistor consists of an insulating body with a resistive surface layer of a mixture of 10−80 wt.% (esp. 46−65 wt.%) of finely divided RuO2, the remainder being glass. Alternative compositions include finely divided Ag and compositions of matter formed by heating RuO2 with a Group V metal oxide, such as NbO5.

Electrode Coating Process

ppg industries inc. Dutch Appl. 69.14899

An anode for brine electrolysis is coated with Ti and a noble metal oxide. An organic Ti compound and a decomposable noble metal compound are applied to the base anode and heated to produce the oxide coating. Ti resinate and Ru resinate are suitable compounds.

Electrode for Electrochemical Processes

imperial chemical industries ltd Dutch Appl. 69.17586

The electrode has a body of refractory coated with a layer of active catalyst. The layer consists of a Pt metal containing a small amount of a Sn, Sb and/or Ge oxide. In an example a Ti body is coated with a mixture deposited from a solution of a Sn alkoxy compound and RuCl3.


Resistance Thermometer

rosemount engineering co. ltd British Patent 1,199,878

A Pt resistance thermometer is designed for use in conditions of high vibration.

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