Platinum Metals Rev., 1970, 14, (2), 72
NEW PATENTS: April 1970
METALS AND ALLOYS
Palladium-Vanadium Resistance Alloys
johnson matthey & co. ltd British Patent 1,171,674
Pd-V alloys having high specific resistance and reduced temperature coefficient of resistance contain 74 to 98.5 wt.% Pd, 1 to 15 wt% V and 0.5 to 11 wt% in total of one or more of the elements Au, Mo or Al.
Manufacture of Titanium Dioxide
laporte titanium ltd British Patent 1,173,593
TiCl4 may be preheated in a tube constructed of refractory material. This is preferably SiO2 or a suitable metal e.g., Pt, a Pt alloy or Pt-lined Inconel.
Constant Conductivity Alloys
trw inc. British Patent 1,173,703 U.S. Patent 3,463,636
The alloys consist of: 70−90 wt% Pt, Rh, Ir, Au or Ag, 7−23 wt% W, 2−8 wt% Re; e.g., 70 wt% Pt, 22.5 wt% W, 7.5 wt% Re.
Sparking Plug Alloy
international nickel co. inc. U.S. Patent 3,466,158
A bonded compound article, e.g., a sparking plug, comprises a Ag component and a high melting point component of Ir, Ru or an Ir-rich or Ru-rich alloy. They are connected by a junction made of a Ag-Pd alloy.
Platinum Metal Ball Bearings, Pivots, Etc
international nickel co inc. U.S. Patent 3,466,165
The difficulty of producing very small balls, pivots for instruments, porous metal filter raw materials from these metals and their alloys are overcome in a matrix system. Small spheres and spheroid-like articles which are predominantly of Ru, Ir, Os or Rh are formed in a molten matrix of other metal and the matrix is then solidified and leached to recover spheres or spheroids. In the examples Pd and Ag form the matrix.
japan gas-chemical co. inc. U.S. Patent 3,469,372
A H2 permeable membrane consists of a Pd or a Pd alloy, the surface of the membrane having a wavy configuration as a result of being stamped with the surface of a plain dutch weave wire netting of 20–200 meshes.
Stabilised Group VIII Metal Alloys
johnson matthey & co. ltd French Patent 1,570,312
The high temperature properties of Group VIII noble metal alloys are stabilised by the presence of up to 20% of a lanthanide, Sc, Y, Ti, V, Zr, Nb, Hf and/or Ta.
Bonding Two Different Metals
johnson matthey & co. ltd German Patent 1,521,335
In bonding metals, e.g., Pt or its alloys to stainless steels, interdiffusion is reduced by interposing a layer of a metal/ceramic mixture. The metal in the layer is insoluble in one of the metals being bonded but is virtually soluble in the other. Mo, W, Nb, Ta and Ti are suitable metals. This corresponds to British Patent 1,093,136.
ELECTRODEPOSITION AND SURFACE COATINGS
Electrodeposition of Palladium
sel-rex corp. British Patent 1,171,734
A plating bath consists of a solution of a urea complex of Pd, adjusted to a pH >8. It is claimed that this prevents porosity previously found in thin (2.5 to 5 μm) Pd coatings.
Plating Platinum Metals on Chromium
e. h. lyons U.S. Patent 3,467,584
A process for plating a Cr surface to provide a corrosion resistant adherent precious metal coating by (a ) depassivating the Cr surface by cathodising it in an acid bath, (b ) rinsing the depassivated surface with a weak acid bath, (c ) plating the depassivated surface from an aqueous acidified solution of an alkali iodide containing Ptl2, PdI2, PdCl2, RhCl3 and/or RhI3.
Platinum Coating Compositions
matthey bishop inc. U.S. Patent 3,470,019
A colloidal dispersion of Pt for use in forming Pt by reaction with a lower alcohol-HCHO mixture is made to contain minor amounts of other Pt group metal, in addition to Pt. When this dispersion is coated on substrates and dried out, adherent, catalytically active Pt deposits are formed. This corresponds to British Patent 1,147,563.
Improved Method of Coating and Inlaying
LABORATORY APPARATUS AND TECHNIQUE
Combustion Detector for Gas Chromato-graphy
u.s. atomic energy commission U.S. Patent 3,460,909
A thermal conductivity compensation device for a catalytic combustion detector has means for dividing the input gas flow to the detector into two equal portions. The first portion of the gas is passed over a heated active Pt filament and the second over a heated deactivated (i.e., V2O5-poisoned) Pt compensation filament.
beckman instruments inc. U.S. Patent 3,468,781
A polarographic cell for determining H2 comprises a pair of electrodes joined by an electrolyte and separated from the test medium by a H2 permeable barrier. The barrier is a gas permeable plastic membrane having a coating of Pd or Ag-Pd alloy of a thickness not greater than 500 Å.
Selective Catalytic Reduction
johnson matthey & co. ltd British Patent 1,159,967
Reduction of a ketone or of an aromatic aldehyde to the corresponding alcohol uses H2 and Pd/charcoal catalyst in the presence of a primary aromatic amine, e.g., C6H5NH2, p -toluidine or benzylamine, or of a heterocyclic tertiary amine, e.g., C5H5N or quinoline. This corresponds to Italian Patent 787,791.
Aliphatic Dinitriles Production
rhone-poulenc s.a. British Patent 1,168,958
Dicyanobutenes and/or adiponitrile are formed from acrylonitrile by heating under pressure in the presence of a Group VIII metal, oxide or hydroxide, e.g., Ru(OH)3.
I.C.E. Exhaust Gas Combustion Catalyst
h. berger British Patent 1,169,719
The catalyst contains Pt and/or Pd (amongst other metals) on refractory supports where the support is ball-milled with catalyst metal solution and the paste coated on a fabric. The layer is dried and calcined to burn away the fabric.
texaco development corp. British Patent 1,170,206
Reforming to give aromatic enrichment is effected in two zones containing Pt metal catalysts with intermediate removal of a lower fraction.
Activation of Hydrocracking Catalysts
esso research & engineering co. British Patent 1,170,647
Hydrocracking catalysts consisting of a Pt group metal on a zeolite are activated with dry H2 (containing less than 10 p.p.m. H2O) and then with an undried gas. Both stages are carried out at elevated temperatures.
Hydrogen Peroxide Production
deutsche gold-und silber-scheideanstalt British Patent 1,171,485
The selectivity of Pd catalysts in the hydrogenation stage is increased by introducing up to 50% of one or more of the other five Pt metals, e.g., 70% Pd − 30%Ir.
Palladium Hydrogenation Catalyst
british petroleum co. ltd British Patent 1,173,469
The catalyst, which retains its activity in the presence of S, consists of Pd (preferably 0.1 to 5 wt%) incorporated by ion-exchange into a zeolite.
Catalyst for Carbonylation
national distillers & chemical corp. British Patent 1,174,747
α, β -Unsaturated acyl halides are produced by reaction of a vinylic halide with CO at elevated temperatures and pressures in the presence of a noble metal catalyst, e.g., Pd, Pt, Ru, Rh, Os, Ir or Pd with a minor amount of Au.
Low Pressure Reforming
chevron research co. British Patent 1,175,022
New catalyst for naphtha reforming consists of 0.01−1% Pt promoted with 0.01−2% Re on an inorganic oxide support.
Alkali-moderated Ruthenium Catalyst
e. i. du pont de nemours & co. British Patent 1,176,336
An alkali-moderated Ru metal catalyst on an Al2O3, BaSO4 or kieselguhr support, suitable for use in hydrogenation reactions, is obtained by mixing a supported Ru catalyst with at least 1 wt% of a basic alkali metal compound. See also British Patent 1,176,337.
soc. belge de l’azote et des produits chimiques du marly s.a. British Patent 1,176,697
A Pt or Pt alloy mesh is used as catalyst for the conversion of NH3 to the oxides of N2.
Noble Metal Condensation Catalysts
montecatini edison s.p.a. British Patent 1,177,233
Alcohols are dimerised in the presence of an alkaline condensing agent and a finely-divided noble metal catalyst (optionally supported). The catalyst may be Rh, Pd, Pt or Ru. The particle size range is: at least 80% less than 150μ; at least 20% less than 50μ.
Catalyst for Manufacture of Vinyl Acetate
b.p. chemicals (u.k.) ltd British Patent 1,177,515
Vinyl acetate is produced by vapour phase reaction of C2H4, O2 and CH3COOH in the presence of a catalyst. The catalyst is a Pt-group metal or Pt group metal compound together with Au or a Au compound. A support of Sn oxide is used.
american cyanamid co. U.S. Patent 3,461,149
The aromatic nitro-compound-CO reaction is catalysed by a supported noble metal and a Lewis acid, e.g., Pd/Al2O3-FeCl3.
Preparation of Dicarboxylic Acids
e. i. du pont de nemours co. U.S. Patent 3,461,160
Oxidation of cyclic olefines to carboxylic acids is effected by contacting the olefines with a liquid phase reaction system comprising aqueous HNO3 and an Os-V catalyst, e.g., comprising 10−70 parts of HNO3, 0.01–0.7 part of V, 0.01–5.0 parts of Os, and 24–90 parts of H2O.
Removal of Ammonia from Gases
universal oil products co. U.S. Patent 3,467,491
NH3 is removed from NH3-containing gases by its conversion to N2 and H2O without the production of harmful N2 oxides by contacting the gases and air with a Pt/Al2O3 catalyst at 400−450°F.
Nitrogen Oxides Removal from Gases
chemical construction co. U.S. Patent 3,467,492
Tail gases from HNO3 production are mixed with CH4 and treated over a series of beds of supported Pt group metal, e.g., usual HNO3 catalysts on Al2O3 or SiO2 gel.
Hydrogenation of Adiponitrile
e. i. du pont de nemours & co. U.S. Patent 3,471,563
Hexamethylene diamine is prepared by reducing adiponitrile in the presence of NH3 and 0.001−10% of Ru catalyst (calculated as metallic Ru on the weight of adiponitrile). The Ru is supported on an inert carrier and is alkali moderated with 0.1−15% of an alkali metal compound (calculated as alkali metal).
catalysts and chemicals inc. U.S. Patent 3,471,583
Pd-Al2O3 catalysts are known to be useful as selective hydrogenation catalysts. However, it is difficult to prepare low surface area Pd/Al2O3 catalysts because their tensile properties are partially destroyed by the necessary heating. Catalysts having superior tensile properties can be made if the Al2O3 matrix is modified with 1−5% Ni-Al2O3 spinel.
Saturated Hydrocarbon Dehydrogenation
institut francais de petrole, des carburants et lubrifiants French Patent 1,567,900
The dehydrogenation catalyst consists of 0.1−2% Pt and 0.01−0.5% Ir deposited on SiO2.
Unsaturated 3C Hydrocarbon Fraction Hydrogenation
farbenfabriken bayer a.g. German Patent 1,518,827
3C hydrocarbon fractions containing unsaturated compounds are treated by trickling them over noble metal catalysts in a virtually stationary H2 atmosphere. A suitable catalyst is 0.5% Pd/Al2O3.
Noble Metal Gas Purification Catalysts
veb leuna-werke walter ulbricht German Patent 1,667,348
An oxidic support is impregnated with a solution of a reducing agent (e.g., HCHO), the surface film is evaporated and then the support is immersed in a solution of a noble metal salt. Pd/Al2O3 for purifying protective gas atmospheres can be obtained in this way.
Unsaturated Ester Production
stamicarbon n.v. Dutch Appln 68.06,541
The olefine-O2-acid reaction is catalysed by a material formed by depositing on a support, such as SiO2 gel, first Pd and then one or more of Pt, Rh and/or Ru. The Pd : Pt group metal (s) ratio is from 300 : 1 to 3 : 1. Subsequently the catalyst is impregnated with a Group IV, VI or VIII metal, e.g., FeCl3.
Oxidation of Ferrous Compounds and Reduction of Ferric Compounds
johnson matthey & co. ltd Canadian Patent 828,669
A feedstock containing Fe2+ or Fe3+ is reacted with O2 or H2 respectively in an acid solution in the presence of a catalyst comprising at least one Pt group metal (Pt, Pd or a Pt-Pd alloy) on an inert support (charcoal) in a trickle column reactor. The feedstock may be obtained from a steel-pickling liquor by extracting Fe ore with H2SO4 or HCl.
Polysiloxane Copolymer Production
rhone-poulenc s.a. British Patent 1,169,290
Excellent yields of polysiloxane-polyoxyalkylene co-polymers are obtained using a Ru carbonyl or diketonate as catalyst.
union carbide corp. British Patent 1,173,570
A catalyst for the production of organosilicon compounds is a nitrile complex of a Pt halide. Examples are: bis(acetonitrile)dichloroplatinum, bis(4-chlorobenzonitrile)dichloroplatinum and bis(lauronitrile)dichloroplatinum.
Platinum Catalysts for SiH addition
general electric co. British Patent 1,175,224
SiH addition to olefines is catalysed by Pt(CH3)3I or Pt(CH3)6.
Palladium Oxidation Catalyst
imperial chemical industries ltd British Patent 1,176,664
An unsaturated organic compound (e.g. C2H4) is oxidised, (e.g. to vinyl acetate) by reaction with a nucleophilic compound in the presence of a Pd compound. These are preferably a palladous halide or carboxylate, and an ionisable cynate.
Ruthenium Catalyst for Dimerisation of Acrylonitrile
mitsubishi petroleum co. ltd British Patent 1,177,059
Acrylonitrile is dimerised by the action of a Ru halide and a metal e.g., Ag in an alcoholic medium.
Catalyst for Condensation of Alcohols
montecatini edison s.p.a. British Patent 1,177,423
Two molecules of primary alcohol are condensed to give a primary alcohol branched at position 2, in the presence of a soluble compound of Rh, Ir, Ru, Os, Pd or Pt.
Platinum Catalyst for Organosilicons
deutsche gold- & silber-scheideanstalt U.S. Patent 3,470,225
The SiH-olefine addition reaction is catalysed by PtX2 (RCOCR′COR″)2 where X is halogen, R is alkyl, preferably, lower alkyl, R′ is H or alkyl, preferably lower alkyl, and R″ is alkyl or alkoxy, preferably lower alkyl or alkoxy.
Palladous Chloride-Acetylene Reaction Product
air reduction co. U.S. Patent 3,474,118
A complex of PdCl2 and C2H2 is prepared by reacting PdCl2 with liquefied C2H2. The complex is useful as a catalyst for the polymerisation and cyclisation of C2H2.
institut francais du petrole, des lubrifiants et carburants French Patent 1,568,741
New catalysts for hydrogenation contain Rh complexed to an amino-derivatives of a phosphine, arsine or stibine.
Acetic Acid Production
institut francais du petrole, des carburants et lubrifiants French Patent 1,568,742
Olefines are oxidised to CH3COOH in the vapour phase and over a Pd−V2O5 catalyst.
Platinum Metal Catalyst
johnson matthey & co. ltd German Patent 1,543,078
A catalyst for the isomerisation of olefines consists of RhCl3.3H2O, PdCl2, RuCl3, IrCl4 and/or H2PtCl6 dissolved in a thermally stable solvent of high viscosity such as polyethyleneglycol, propylene glycol, glycerol or pinacol. This corresponds to British Patent 1,116,943.
atlantic richfield co. British Patent 1,177,265
In a fuel cell, means are provided to maintain the Pd membrane in the anode negative to the cathode during periods of lowered H2 supply, so that the membrane is not corroded by the electrolyte.
Fuel Cell Electrode
general electric co. (new york) U.S. Patent 3,461,044
An intimately blended codeposit of a Pt metal and a wet-proofing polymer is formed from a bath containing from 0.1 to 10% Pt metal and 0.1–50% of polymer. A substrate is immersed in the plating bath and a current of 10–25 mA/cm2 is applied to the substrate with polarity being reversed at 10–60 second intervals. The coated substrate may be used as an electrode in a cell such as a fuel cell.
Magnesium Anode Primary Cell
united states secretary of the navy U.S. Patent 3,462,309
A primary cell has a Mg anode and an inert metal cathode which is a metal wire screen of from 8–40 mesh having an outer surface of granular Pd plating which may be deposited in an intervening stage of electroless Ni plating.
Fuel Cell Electrode
leesona corp. U.S. Patent 3,467,554
An electrochemical cell uses an electrode which contains a Pd-Au alloy having from 35 to 82 at.% Au and the remainder Pd, as the catalytic material. The alloy in black form is mixed with hydrophobic polymer particles to provide improved results.
Fuel Cell Electrode
atlantic richfield co. U.S. Patent 3,470,031
A process for the preparation of a fuel electrode for a fuel cell by intimately mixing PtO2 and Ag powder in a weight ratio of 0.1−5 : 1, pressing the mixture between two Ag screens to form an electrode body and reducing the body to a stage of reduction between 50%−95% relative to the stoichiometrically calculated stage where the theoretical value for the formation of PtH is 125.2%.
Hydrogen Separation Foil or Tube
varta a.g. British Patent 1,168,457
Non-porous bodies for H2 separation and purification are made by forming an alloy of a hydrogen-absorbing metal (e.g., Pd) and a less noble metal. The latter is leached out from the powdered alloy to leave the hydrogen-absorbing metal in the form of a non-pyrophoric powder. This is compacted with a binder to form the body.
Electrolytic Cell Construction
imperial metal industries (kynoch) ltd British Patent 1,168,558
The electrode assemblies consist of a plurality of parallel electrodes, e.g., Pt-coated Ti, with steel, Cu or Al spacers clamped together to give electrical contact.
Palladium Electrode for Electrolytic Production of Hydrogen
milton roy co. British Patent 1,177,219
The cathode in an electrolytic cell consists of a tube (closed at one end) of Pd or a H2-permeable Pd alloy. The surface of the tube is activated to increase H2 permeability so that virtually all of the gas generated is recovered in ultra-pure form. The activation process consists of contacting the clean surface with a molten alkali or alkaline earth metal hydroxide and then exposing the treated surface at not less than 450°C to an O atmosphere.
Activation of Platinum Metal Electrodes
johnson matthey & co. ltd Japan Patent 554,329
Particularly active electrodes for brine electrolysis are produced by exposing a Ti electrode plated with Pt group metal or alloy, in particular Pt, Pt-Rh or Pd-Ag, to the action of Hg vapour or alkali metal amalgam vapour, the Hg coating being distilled off after it has been deposited to leave the surface in a highly active state. This corresponds to British Patent 957,703.
ELECTRIC AND ELECTRONIC ENGINEERING
Metal Contact on a Semiconductor
international business machines corp. British Patent 1,174,832
The contact consists of three layers. These are (outwards from the semiconductor): (1) vacuum-deposited Pt, (2) electroless-plated Pd, and (3) Al or Mo.
bendix corp. U.S. Patent 3,460,241
A method is described of mounting Si semiconductor elements on a thick film circuit using a mixture of Pt and Au to form a Au-Si eutectic bond.
nippon electric co. ltd U.S. Patent 3,461,071
Piezoelectric ceramic has the general formula Pb(ZrxTiySnz)O3 where the subscripts are molar fractions and x=0−0.9, y=0.1−0.6, z=0−0.65, and x+y+z=1.00, and is improved by two additives, the first being 0.01−50−wt% MnO and the second 0.01−30 wt% IrO2 and 0.01−50 wt% Cr2O3.