Showing papers on "Noble metal published in 1970"
TL;DR: In this paper, the pre-steady-state oxidation of a wide range of binary alloys of practical importance, in 1 atm oxygen at 600° C, is discussed in terms of the main determining parameters, namely the free energies of formation and growth rates of the component and complex oxides, the bulk alloy composition, the alloy interdiffusion coefficient, the oxygen solubility and diffusivity in the alloy, and effects such as epitaxy.
Abstract: The pre-steady-state oxidation of a wide range of binary alloys of practical importance, in 1 atm oxygen at 600° C, is discussed in terms of the main determining parameters, namely the free energies of formation and growth rates of the component and complex oxides, the bulk alloy composition, the alloy interdiffusion coefficient, the oxygen solubility and diffusivity in the alloy, and effects such as epitaxy. Schematic diagrams are used to illustrate the morphology and structure of the films, as revealed by electron microscopy and diffraction. After tabulation of the sparse, and often apparently unreliable, fundamental parameters, a comparison is made within each of the following groups of alloys: (1) Fe-Cr, Ni-Cr, and Co-Cr alloys, in which the less noble metal is the same and the noble metal is varied, there being composition ranges in which noble metal oxide and less noble metal oxide respectively predominate but in which the oxides are partially miscible or react. (2) Ni-Al, Ni-Cr, Ni-Si, Ni-Mn, and Ni-Co alloys, in which the noble metal is the same, the less noble metals have a wide range of affinities for oxygen and oxidation rates, and the oxide phases produced include solid solutions, largely immiscible simple oxides, and complex oxides. (3) Cu-Ni, Cu-Zn, and Cu-Al alloys, in which the noble metal is the same and the less noble metal is varied, the oxides being largely immiscible.
155 citations
65 citations
TL;DR: The authors discusses the noble metal catalysts as a group, points out similarities and differences among the metals relevant to the hydrogenation of natural oils, and describes some of the practical applications of catalysis by palladium.
Abstract: Studies in the hydrogenation of natural oils with catalysts of the platinum metals group have been limited mainly to platinum and palladium with only scant attention to rhodium, ruthenium, iridium and osmium. This preference was dictated largely by economics, palladium being the only noble metal catalyst truly competitive on a usecoat basis with nickel in the hydrogenation of low-priced oils. This paper discusses the noble metal catalysts as a group, points out similarities and differences among the metals relevant to the hydrogenation of natural oils, and describes some of the practical applications of catalysis by palladium.
48 citations
TL;DR: In this paper, the electronic band structure of copper was calculated using the empirical pseudopotential method and a nonlocal $d$-wave potential with a damping factor was used to provide the potential for the electron.
Abstract: The electronic band structure of copper is calculated using the empirical pseudopotential method. A nonlocal $d$-wave potential with a damping factor is used to provide the potential for the $d$ electron. The results agree well with the available experimental data and with theoretical band calculations using other methods. It is anticipated that the empirical pseudopotential method can be used for other noble metals and even extended to noble metal compounds, transition metals, and transition metal compounds.
39 citations
TL;DR: In this article, the insertion reaction of cyclohexyl isocyanide with π-allylpalladium chloride in benzene at room temperature gave di-μ-chloro-bis[1-(cyclohexylimino)-3-butenyl]-bis(cyclohexymethylisocyanides)dipalladium by insertion reaction was followed by NMR spectroscopy.
36 citations
Patent•
03 Aug 1970
TL;DR: In this paper, a group VIII noBLE METAL COMPONENET CATALYST is used in a FIXED-BED system with a group of C4-ACETYLENES.
Abstract: SELECTIVE HYDROGENATION OF C4-ACETYLENES, FOR EXAMPLE ETHYACETYLENE AND/OR DIMETHYLACETYLENE, IN ADMIXTURE WITH BUTADIENE, IS EFFECTED IN A FIXED-BED SYSTEM USING A GROUP VIII NOBLE METAL COMPONENET CATALYST. A PREFERRED CATALYST COMPRISING PALLADIUM IN AN AMOUNT OF ABOUT 0.01% TO ABOUT 0.2% BY WEIGHT. OPERATING CONDITIONS INCLUDE A TEMPERATURE OF FROM 35*C. TO ABOUT 70*C. AND A PRESSURE IN THE RANGE OF ABOUT 10 P.S.I.G. TO ABOUT 40 P.S.I.G. CATALYST STABILITY IS IMPROVED SINCE THE GROUP VIII METAL COMPONENTS IS SURFACE-IMPREGNATED ONTO THE POROUS CARRIER MATERIAL.
34 citations
31 citations
TL;DR: In this article, experimental methods that are especially promising for deciding whether a non-electrochemical or an electrochemical mechanism prevails for a particular compound are presented, based on experimental results.
21 citations
Patent•
30 Apr 1970
TL;DR: A WIRE OF IRIDIUM or IRIDOME and its noBLE METAL ALLOYS is TREATED in a MANNER that MAKES IT USEFUL as an ELECTRODE for SENSING HYDROGEN ION CONCENTRATION OF PH OF BLOOD OR Other Fluid as discussed by the authors.
Abstract: A WIRE OF IRIDIUM OR IRIDIUM AND ITS NOBLE METAL ALLOYS IS TREATED IN A MANNER THAT MAKES IT USEFUL AS AN ELECTRODE FOR SENSING HYDROGEN ION CONCENTRATION OF PH OF BLOOD OR OTHER FLUID. THE ELECTRODE MAY BE ADMITTED TO A BLOOD VESSEL THROUGH A SMALL CANNULA. VARIATIONS IN THE DIFFERENCE BETWEEN THE POTENTIALS DEVELOPED BY THE NEW ELECTRODE AND A SUITABLE REFERENCE ELECTRODE ARE METERED AND LINEARILY RELATED TO PH CHANGES.
20 citations
TL;DR: In this paper, the authors describe optical studies which show that the noble metal-noble metal alloys are of two types, i.e., the electron energy bands shift smoothly as the concentration varies and the rates and directions of shift are determined by a competition between lattice constant and potential effects.
20 citations
Patent•
02 Feb 1970TL;DR: In this article, an acidic plating solution containing a salt of a noble metal catalyst is forced through the pores of a nickel electrode substrate and the noble metal ions from the dissolved salt replace a thin layer of the nickel surface within the pores.
Abstract: A porous or sintered fuel cell electrode which is catalyzed by means of a replacement plating process. An acidic plating solution containing a salt of a noble metal catalyst is forced through the pores of a nickel electrode substrate and the noble metal ions from the dissolved salt replace a thin layer of the nickel surface within the pores.
Patent•
15 Jul 1970
TL;DR: In this article, the authors describe a group of VIII NOBLE METAL, TIN and an INORGANIC, SOLID, this articleACTORY OXIDE CARRIER.
Abstract: COMPOSITES OF A GROUP VIII NOBLE METAL, TIN AND AN INORGANIC, SOLID, REFRACTORY OXIDE CARRIER HAVE EXCELLENT DEHYDROGENATION ACTIVITIES AND LITTLE OR NO ISOMERIZATION AND CRACKING ACTIVITIES.
Patent•
26 Feb 1970TL;DR: In this paper, acid chloride solutions of noble metals are prepared; the metal is precipitated as a metal-ammonia complex and then reduced to yield a relatively coarse noble metal precipitate powder.
Abstract: Acid chloride solutions of noble metals are prepared; the metal is precipitated as a metal-ammonia complex and then reduced to yield a relatively coarse noble metal precipitate powder. Metallization compositions containing the noble metal powders are printed and fired to form various electrical circuit components.
TL;DR: The mechanism of the hydrogenation of quinone, allyl alcohol and vinyl acetate in acidic aqueous solutions on Pt and Pd-Ag as catalysts has been investigated in this article.
TL;DR: In this article, values of Kondo temperatures and saturation hyperfine fields have been measured for Cr as a dilute impurity in Cu, Ag, and Au, and they have been shown to be stable.
Patent•
30 Mar 1970
TL;DR: In this paper, the authors provided a substantially neutral catalyst containing (a) alumina, (b) from 0.05 to 2 percent by weight of platinum, (c) from 1.01 to 0.5 percent of at least one additional noble metal from the group consisting of iridium and ruthenium, the latter percentages being given with respect to alumina.
Abstract: For dehydrogenating saturated hydrocarbons, there is provided a substantially neutral catalyst containing (a) alumina, (b) from 0.05 to 2 percent by weight of platinum, (c) from 0.01 to 0.5 percent by weight of at least one additional noble metal from the group consisting of iridium and ruthenium, the latter percentages being given with respect to alumina, wherein the content by weight of the additional noble metal is from 0.05 to 0.3 times the content by weight of platinum and (d) an alkali or alkalineearth metal with a content by weight of from 0.3 to 10 times the overall content of noble metals, the specific surface of the catalyst being 1 to 20 sq. m. per gram and the neutralization heat of the alumina being below 5 calories per gram in the ammonia adsorption test. Of the above catalysts, the best are produced by introducing the alkali or alkaline-earth metal compound after the noble metals are introduced.
01 Jun 1970
TL;DR: In this paper, a model for the stacking fault energy, γ, in noble metals and their alloys is developed which qualitatively explains many features of experimental observations, based on bothd band and free electron contributions to the cohesion.
Abstract: A model for the stacking fault energy, γ, in noble metals and their alloys is developed which qualitatively explains many features of experimental observations. The model is based on bothd band and free electron contributions to the cohesion. An important prediction of the model is that γ can be decreased in noble metal alloys by the addition of a solute with an emptyd band withZ = 1 (i.e., lithium in silver). Measurements of γ were made as a function of lithium concentration in a series of Ag-Li alloys up to 25 at. pct Li using the node method. The results show that γ decreases with the addition of lithium in a manner predicted by the model.
Patent•
04 May 1970TL;DR: In this paper, a process for the in situ leaching of noble metal values from ores is described, which comprises feeding into a subterranean stratum chlorinated aqueous brine having an oxidation potential of at least about 500 millivolts.
Abstract: Disclosed herein is a process for the in situ leaching of noble metal values from ores. The process comprises feeding into a subterranean stratum chlorinated aqueous brine having an oxidation potential of at least about 500 millivolts. Noble metal values are solubilized into the brine which is then recovered from the stratum. The process is relatively efficient and economical and can be performed without complex, time-consuming excavations or the accumulation of processed tailings.
Patent•
08 Jan 1970
TL;DR: In this article, the authors describe a process for the recovery of noble metals from noble metal containing substances by subjecting such substances- preferably in comminuted form-to the action of a solvent preferably comprising diacetone alcohol as a major component, water, minor amounts of glacial acetic acid potassium iodide and elemental iodine.
Abstract: Processes for and compositions utilized in the recovery of noble metals from noble metal containing substances by subjecting such substances- preferably in comminuted form- to the action of a solvent preferably comprising diacetone alcohol as a major component, water, minor amounts of glacial acetic acid potassium iodide and elemental iodine. Solvation of the noble metal occurs during agitation and heating of the slurry. The noble metal contents are removed from the noble metal pregnant solution by displacement onto a non-noble metal surface. The solid noble metal containing residue is treated with sufficient aqueous hydroxide solution to convert excess non-noble metal into its water-soluble salt. The remaining insoluble material containing the noble metal recovered is rinsed to remove any remaining unreacted alkali and the soluble salts and is then digested with concentrated sulfuric acid to dissolve any remaining acid soluble impurities, the remaining acid insoluble residue is rinsed, dried and comprises substantially pure noble metal.
Patent•
05 Nov 1970TL;DR: In this paper, a method of applying a controlled emittance to a noble metal selected from the group including ruthenium, rhodium, palladium, osmium, iridium and platinum, and intra-alloys thereof is described.
Abstract: A method of applying a controlled emittance to a noble metal selected from the group including ruthenium, rhodium, palladium, osmium, iridium and platinum, and intra-alloys thereof. The coating is applied by plasma arc spraying modified alumina on a surface of one of the noble metals group, the alumina being modified by having a hydrochloric acid washed alumina powder contain a dispersion of a noble metal black selected from the above group.
TL;DR: In this article, the authors show that molecular oxygen is adsorbed on alloys ofmercury with Pt, Au, Ir and Rh, from solutions in acetonitrile, dimethylformamide and dimethylsulphoxide, reaching 200-800 μC cm−2.
Patent•
26 Aug 1970
TL;DR: In this article, the NoBLE METAL OXIDE HYDROGENATION PROMOTER was improved by converting the noBLE metals to its CORRESPONDING SULFIDE form, the SULfide to the CORRESpONDing HYDROXIDE, the HYDRoxide to CORRES-PONDing NOBLE METALS AMMINE COMPLEX and thereafter DECCOMPOSING the AMmine COMPLEX in a OXIDIZING ATMOSPHERE FOLLOWED by an ACTIVATION by RED
Abstract: THE CATALYTIC ACTIVITY OF CATALYST COMPOSITIONS COMPRISING A ZEOLITIC ALUMINOSILICATE IN CONJUNCTION WITH A GROUP VII NOBLE METAL OXIDE HYDROGENATION PROMOTER ARE IMPROVED BY CONVERTING THE NOBLE METAL TO ITS CORRESPONDING SULFIDE FORM, THE SULFIDE TO THE CORRESPONDING HYDROXIDE, THE HYDROXIDE TO THE CORRESPONDING NOBLE METAL AMMINE COMPLEX AND THEREAFTER DECCOMPOSING THE AMMINE COMPLEX IN A OXIDIZING ATMOSPHERE FOLLOWED BY AN ACTIVATION BY REDUCTION IN HYDROGEN.
Patent•
27 Apr 1970TL;DR: In this article, an ELECTRODE is described, which has a CATALYTIC COATING of PLATINUM, PALLADIUM, and a THIRD LESS NOBLE METAL on a substrate.
Abstract: AN ELECTRODE IS DESCRIBED WHICH HAS A CATALYTIC COATING OF PLATINUM, PALLADIUM, AND A THIRD LESS NOBLE METAL ON A SUBSTRATE. SUCH AN ELCECTRODE PROVIDES A HIGH PERFORMANCE ANODE FOR ELECTROCHEMICAL CELLS.
Patent•
26 Feb 1970TL;DR: In this article, acid chloride solutions of noble metals are prepared; the metal alloy is precipitated as an alloy-ammonia complex and then reduced to yield a relatively coarse noble metal alloy precipitate powder.
Abstract: A method of preparing alloy powders which exhibit low, if any, catalytic activity. Acid chloride solutions of noble metals are prepared; the metal alloy is precipitated as an alloy-ammonia complex and then reduced to yield a relatively coarse noble metal alloy precipitate powder. The important process parameters include the particular chemical reagents utilized, pH control and the rates of precipitation and reduction.
Patent•
13 Jul 1970
TL;DR: PALLADIUM ALONE, OR MIXED with other METALS of the PLATINUM GROUP on a SILICA CONTAINING CARRIER USED in the HYDROGENATION STEP of the ANTHRAQUINONE PROCESS for PRODUCING HYDRogen PEROXIDE is regenerated by an OXIDATION TREATMENT at a PH BELOW 7 FOLLOWED by a REDUCTION TREATment at a TEMPERATURE BELOW 200*C, PREFERABLY BELOW 150*C as discussed by the authors.
Abstract: PALLADIUM ALONE, OR MIXED WITH OTHER METALS OF THE PLATINUM GROUP ON A SILICA CONTAINING CARRIER USED IN THE HYDROGENATION STEP OF THE ANTHRAQUINONE PROCESS FOR PRODUCING HYDROGEN PEROXIDE IS REGENERATED BY AN OXIDATION TREATMENT AT A PH BELOW 7 FOLLOWED BY A REDUCTION TREATMENT AT A TEMPERATURE BELOW 200*C., PREFERABLY BELOW 150*C.
Patent•
20 Aug 1970TL;DR: In this paper, a noBLE-METAL SALT is added to the seams of the gold salts before or during the conversion step. But the effect of this salt on the sensitivity of the salts is not discussed.
Abstract: CONVERSION-TYPE SILVER HALIDE EMULSIONS ARE MADE BY ADDING A NOBLE-METAL SALT TO THE EMULSION BEFORE OR DURING THE CONVERSION STEP. IN ONE EMBODIMENT, GOLD SALTS, WHICH ARE GENERALLY KNOWN AS SILVER HALIDE SENSITIZERS, ARE ADDED AFTER INITIAL FORMATION OF THE GRAIN IN THE CONVERSION PROCESS AND BEFORE 80% OF THE CONVERSION STEP IS COMPLETE. IMPROVED INTERNAL-RADIATION SENSITIVITY IS OBSERVED IN CONVERTED-TYPE EMULSIONS MADE BY THIS PROCESS.
Patent•
06 Jul 1970
TL;DR: A typical process comprises contacting ethylene, carbon monoxide and water with a liquid reaction medium containing rhodium trichloride and triphenylphosphine to produce dihydrodimethylethylpyridine as discussed by the authors.
Abstract: Substituted pyridines are prepared by reacting an ethylenically unsaturated hydrocarbon, carbon monoxide, water and ammonia in a liquid medium containing a Group VIII noble metal catalyst in complex association with a biphyllic ligand or an aromatic heterocyclic amine at a temperature of 50* to 400* C and a pressure of 5 to 300 atmospheres. A typical process comprises contacting ethylene, carbon monoxide and water with a liquid reaction medium containing rhodium trichloride and triphenylphosphine to produce dihydrodimethylethylpyridine.
Patent•
07 Dec 1970TL;DR: In this article, a photo-graphic SILVER DIFFUSION TRANSFER process was used to expose a movie unit to the public, in an effort to enhance the stability of a SILVER image.
Abstract: THE PRESENT INVENTION RELATES TO A PHOTOGRAPHIC SILVER DIFFUSION TRANSFER PROCESS WHICH COMPRISES, IN ESSENCE, EXPOSING A SILVER DIFFUSION TRANSFER FILM UNIT WHICH COMPRISES PHOTOSENSITIVE SILVER HALIDE AND SILVER PRECIPITATING NUCLEI; CONTACTING THE EXPOSED FILM UNIT WITH A PROCESSING COMPOSITION WHICH COMPRISES A SILVER HALIDE DEVELOPING AGENT AND A SILVER HALIDE SOLVENT TO PROVIDE A VISIBLE SILVER IMAGE TO THE UNIT, AS A FUNCTION OF EXPOSURE; AND COACTING THE SILVER IMAGE WITH A NOBLE BELOW SILVER IN THE ELECTROMOTIVE FORCE SERIES OF ELEMENTS AT A CONCENTRATION EFFECTIVE TO ENHANCE STABILITY OF A SILVER IMAGE PROVIDED BY DIFFUSION TRANSFER PROCESSING OF THE FILM UNIT.
Patent•
10 Mar 1970
TL;DR: In this paper, it has been found that due to the formation of a galvaneic ELEMENT, the LESS NOBLE METAL LAYER DISSOLVES ParticULARly RAPIDly.
Abstract: THE INVENTION RELATES TO A METHOD OF MANUFACTURING AN ELECTRIC DEVICE, IN WHICH A SUBSTRATE HAS TO BE PROVIDED BY ETCHING FOR EXAMPLE WITH A FINE CONTACT PATTERN IN TWO LAYERS CONSISTING OF A LESS NOBLE METAL AND A NOBLER METAL RESPECTIVELY. IT HAS BEEN FOUND THAT PRESUMABLY DUE TO THE FORMATION OF A GALVANIC ELEMENT THE LESS NOBLE METAL LAYER DISSOLVES PARTICULARLY RAPIDLY. THIS CAN BE PREVENTED BY COVERING THE NOBLER METAL LAYER AND A STRIP OF THE LESS NOBLE METAL LAYER WITH AN INSULATING LAYER PRIOR TO ETCHING OF THE LAST-MENTIONED LAYER.
Patent•
26 Oct 1970TL;DR: In this article, a reactive sensor is described, which has a gas diffusion CATHODE, an ANODE SPACED from the cathode, the ANODE with a CATALYTIC COATING of PLATINUM, PALLADIUM, and a third less noBLE METAL on a SUBSTRATE.
Abstract: A REACTANT SENSOR IS DESCRIBED WHICH HAS A GAS DIFFUSION CATHODE, AN ANODE SPACED FROM THE CATHODE, THE ANODE WITH A CATALYTIC COATING OF PLATINUM, PALLADIUM, AND A THIRD LESS NOBLE METAL ON A SUBSTRATE THE CATHODE BEING LARGER THAN THE ANODE IN A GEOMETRIC AREA RATIO OF AT LEAST 3 TO 1, AND A CURRENT METER CONNECTED ACROSS THE CATHODE AND ANODE.