Platinum aluminium

Most effort over the electrochemical reduction of benzene hydrocarbons has centred on finding a reaction medium, which is also a better solvent for the substrate than liquid ammonia. Aliphatic amines have proved useful solvents and they may be used in an undivided electrochemical cell. Base is generated at the cathode while an equivalent of acid is generated in the anode reaction so that mixing of the cel contents maintains a neutral solution. An alcohol is usually added as a proton donor to prevent the build-up of a localised highly basic environment. The simultaneous anode reaction is oxidation of the amine. Electrodes of platinum, aluminium or graphite have been used. Under these conditions, benzene [38] is converted... 

According to J. W. Dobereiner, if zinc together with iron be immersed in a soln. of potassium hydroxide containing a nitrate, ammonia is formed, while if the nitrate be absent, hydrogen alone is evolved. F. Schulze showed that all the nitrate- or nitrite-nitrogen is transformed into ammonia by the action of zinc, zinc and platinum, aluminium, or sodium-amalgam on alkali soln. of nitrates or nitrites. E. J. Mills and T. U. Walton found that sulphates favour the reaction the more sulphate present the quicker the reduction. The reaction was examined by W. Wolf, A. V. Harcourt, and M. Siewert. The reaction is rather important, because upon it is based a method for determining the quantity of nitrites and nitrates in potable water. 

It wTas found that nickel has no effect upon the catalytic activity of the platinum aluminium, cobalt, and bismuth reduce its activity appreciably whilst copper, zinc, silver, tin, and iron inhibit its activity altogether. 

The sample to be studied is placed in the sample holder or crucible, which is mounted on (or suspended from) the weighing arm of the microbalance. A variety of crucible sizes, shapes and materials used (Figure 4.4). The melting point of the crucible should be at least 100 K greater than the temperature range of the experiment and there must be no chemical reaction between the crucible and the sample. Crucibles are typically made from platinum, aluminium, quartz or alumina (a ceramic), but crucibles made from other materials are available. The crucible should transfer heat as uniformly and as efficiently as possible to the sample. The shape, thermal conductivity and thermal mass of... 

Chlorosulfonic acid-aluminium oxide was active as a heterogeneous catalyst in promoting the isomerization of tricyclic naphthenes to adamantmes. This mixture was one of six catalysts examined to determine their activity in facilitating the gas-phase isomerization of perhydroacenaphthene to alkyladamantanes, the most active catalyst was a mixture of thionyl chloride-activated platinum-aluminium oxide. ... 

A pletliora of different SA systems have been reported in tire literature. Examples include organosilanes on hydroxylated surfaces, alkanetliiols on gold, silver, copper and platinum, dialkyl disulphides on gold, alcohols and amines on platinum and carboxyl acids on aluminium oxide and silver. Some examples and references can be found in [123]. More recently also phosphonic and phosphoric esters on aluminium oxides have been reported [124, 125]. Only a small selection out of tliis number of SA systems can be presented here and properties such as kinetics, tliennal, chemical and mechanical stability are briefly presented for alkanetliiols on gold as an example. 

Experimental values for tire sputtering efficiency tend to show lower values of a for elements, such as aluminium and mngsten which form stable oxides, compared with the metals such as gold and platinum which do not under normal experimental conditions. This is probably due to the presence of a surface oxide, since industrial sources of argon, which are used as a source of ions for example, usually contain at least 1 ppm of oxygen, which is more than enough to oxidize aluminium and tungsten. 

Another problem in the construction of tlrese devices, is that materials which do not play a direct part in the operation of the microchip must be introduced to ensure electrical contact between the elecuonic components, and to reduce the possibility of chemical interactions between the device components. The introduction of such materials usually requires an annealing phase in the construction of die device at a temperature as high as 600 K. As a result it is also most probable, especially in the case of the aluminium-silicon interface, that thin films of oxide exist between the various deposited films. Such a layer will act as a banier to inter-diffusion between the layers, and the transport of atoms from one layer to the next will be less than would be indicated by the chemical potential driving force. At pinholes in the AI2O3 layer, aluminium metal can reduce SiOa at isolated spots, and form the pits into the silicon which were observed in early devices. The introduction of a tlrin layer of platinum silicide between the silicon and aluminium layers reduces the pit formation. However, aluminium has a strong affinity for platinum, and so a layer of clrromium is placed between the silicide and aluminium to reduce the invasive interaction of aluminium. 

Nickel on nickel Gold on gold Platinum on platinum Copper on copper Indium on indium Lead on lead Aluminium on aluminium Silver on silver Iron on iron Tin on tin Steel on tin alloy Steel on steel Steel on Pb alloy Steel on Al. bronze Steel on cast iron Steel on brass Steel on bronze Steel on Pb. brass... 

Metal considered platinum, rhodium, silver aluminium bronzes, tin bronzes, gunmetals brasses, nickel silvers Nickel Lead, On and soft solders and cast iron... 

By a mechanism similar to that discussed in relation to platinum coating, titanium can function as a conducting jig to support aluminium components and assemblies in conventional anodising baths. In this application the exposed titanium acquires the insulating film, but allows current to pass to the aluminium at the points of contact . 

Bursting discs may be fabricated of gold, silver, platinum or palladium. The recommended maximum temperatures for continuous use are 80 C for gold, 150 C for silver, 300 C for palladium and 450 C for platinum. Figure 6.6 gives bursting pressure/disc thickness data for these metals and for aluminium and nickel. 

This material can be used only in seawater or similar chloride-containing electrolytes. This is because the passivation of the silver at discontinuities in the platinum is dependent upon the formation of a film of silver chloride, the low solubility of which, in seawater, inhibits corrosion of the silver. This anode, consisting of Pt-lOPd on Ag, was tried as a substitute for rapidly consumed aluminium, for use as a trailing wire anode for the cathodic protection of ships hulls, and has been operated at current densities as high as 1 900 AmHowever, the use of trailing anodes has been found inconvenient with regard to ships manoeuvrability. 

High- silicon/ iron Magnetite Steel Iron Cast iron Pb-65b- lAg Lead/ platinum Graphite Aluminium Zinc Coke breeze... 

Temperature resistance, i.e. a combination of melting point and oxidation resistance, may be of prime importance. A general correlation exists between melting point and hardness since both reflect the bond strength of the atoms in the crystal lattice, and the preferred order of coating metals for use in high temperature applications as temperature is increased is silver, aluminium, nickel, rhenium, chromium, palladium, platinum and rhodium. 

Non-ionic thiourea derivatives have been used as ligands for metal complexes [63,64] as well as anionic thioureas and, in both cases, coordination in metal clusters has also been described [65,66]. Examples of mononuclear complexes of simple alkyl- or aryl-substituted thiourea monoanions, containing N,S-chelating ligands (Scheme 11), have been reported for rhodium(III) [67,68], iridium and many other transition metals, such as chromium(III), technetium(III), rhenium(V), aluminium, ruthenium, osmium, platinum [69] and palladium [70]. Many complexes with N,S-chelating monothioureas were prepared with two triphenylphosphines as substituents. 

Stainless steel, mild steel under normal temperature and pressure Silver, platinum and tantalum, carbon, graphite for wet gas. At higher pressures use extra heavy black iron pipe. High-pressure steel. Monel or aluminium-iron-bronze valves... 

Most common metals Cast iron and stainless steel <120 C, steel =s175°C, Inconel, nickel and platinum 400°C Most common metals Glass, stainless steel, copper, Monel or nickel 200 C. At higher temperatures only nickel and Monel are recommended Glass, stainless steel. Teflon Hypalon, aluminium Tygon PVC and polythene... 

According to anomalous small angle X-ray scattering (ASAXS), this compound slowly decomposes to release redispersible platinum nanoclusters with a mean diameter of 1.2 nm. The protective shell is formed on site by excess aluminium organics. 

At the m.p. of aluminium (600°C) an aluminium-sheathed palladium thermocouple formed an alloy with a flash and an exotherm to 2800°C [1]. The use of thin layers of palladium or platinum on aluminium foil or wire as igniters derives from the intense heat of alloy formation, which is sufficient to melt the intermetallic compounds [2],... 

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