Chloroplatinic acid, solution

Three carbon powders from three different commercial manufacturers were used to make six catalysts. For each carbon, two types of catalysts, namely HEC and HDC, were prepared using slurry-phase preparation methods. For the HDC catalysts a chloroplatinic acid solution containing the requisite amount of Pt (to generate a nominal 1.5 wt% Pt/CP) was added to an alkaline CP slurry. This was... 

Ferric salts are reduced to the ferrous condition and chromates are reduced to chromic salts. Salts of gold, silver, copper, antimony, bismuth and mercury are reduced to the free metals, which are frequently obtained as colloidal solutions if the original solutions are weak with the exception of the first-named there is a tendency for the liberated metal to be accompanied by sulphide, especially if excess of hydrosulphite is used.7 Chloroplatinic acid is reduced to red chloroplatinous acid solution. Tellurous and telluric acids, selenious acid and arsenic compounds, are reduced to the free elements.8... 

M Ethanolic chloroplatinic acid solution dissolve l.OOg of chloroplatinic acid (40% platinum metal) in 10 ml of absolute ethanol. 

Preparation of Pt-TiOx/Pd membranes. It was also desirable to prepare metalloceramic membranes in which the catalytic activity of the ceramic phase was enhanced through the addition of a noble metal. The very low surface area of the titania films prepared as described above made them difficult to impregnate with adequate dispersion by traditional incipient wetness techniques. Instead, finely ground titania (>200 mesh) was impregnated with platinum via the incipient wetness method with a chloroplatinic acid solution. This powder was then sprinkled onto the surface of a freshly dipped membrane, which was dried and heat treated as described. These materials were activated before use at 350°C in hydrogen for three hours. 

Nishimura prepared a platinized T-4 Raney nickel by platinizing and simultaneously leaching Raney alloy specifically, chloroplatinic acid solution, made alkaline with a small amount of sodium hydroxide, was added to a suspension of Raney alloy in water.91 The partly leached and platinized Raney alloy was then developed in water, forming a large quantity of bayerite. Partial loss in activity of Raney nickel, which may result on treatment with chloroplatinic acid, could be avoided in this way, and the platinized Raney nickel thus obtained showed a better activity than that platinized by the method of Delepine and Horeau in hydrogenation of typical organic compounds including ketones such as cyclohexanone and acetophenone. 

Pyrex test-tubes fitted with corks or rubber stoppers and labelled with particulars of the size of drop delivered. It must be pointed out that new smooth platinum wire allows liquids to drop off too readily, and hence it is essential to roughen it by dipping into chloroplatinic acid solution, followed by heating to glowing in a flame this should be repeated several times. Micro burettes sometimes find application for the delivery of drops. 

Chloroplatinic acid solution pale-yellow precipitate of thallium(I) hexachloroplatinate(IV) Tl2[PtCl6], almost insoluble in water (solubility 0-06 g i 1 at 15°C). 

Catalysts can be contained in the membrane pores or on the membrane surface by several impregnation and adsorption techniques commonly used for conventional catalyst preparation. To introduce catalyst inside the pores, for example. Sun aixl Khang [1988] use chloroplatinic acid solution to impregnate Ft catalyst in porous glass membrane pores. Ni, Fe Ag, and Pd catalysts of varying particle sizes can be deposited in porous alumina membranes by immersing the membrane in an electrolysis bath of a... 

Pt Chloroplatinic acid solution Porous Vycor glass Champagnie et al. [1990a]... 

Prepare platinized asbestos as follows put 5 g of purified asbestos into a bowl and pour a 1-2% chloroplatinic acid solution over it. Transfer the fibres impregnated with the solution into a porcelain crucible and roast them first carefiuly, and then strongly on a blowtorch. Store the prepared catalyst in a jar with a ground-glass stopper. Roast the platinized asbestos without fail before each experiment. 

Fig. 13.6. Concentration profiles of platinum distribution through support particles after impregnation of carbon and alumina with 1) aqueous chloroplatinic acid solutions and 2) acetone chloroplatinic acid solutions. (Redrawn using data from Ref. 65.)...

Platinum-silica-alumina (1% Pt by wt) was prepared by impregnation of a commercial cracking catalyst (6% alumina) with chloroplatinic acid solution, drying, and reduction under hydrogen. 

One common refomiing catalyst is platinum on alumina. Platinum on alumina (AUOO (see SEM photo below) is a bifunctional catalyst that can be prepared by exposing alumina pellets to a chloroplatinic acid solution, drying, and then heating in air 775 to 875 K for several hours. Next, the material is exposed to hydrogen at temperatures around 725 to 775 K to produce very small clusters of Pt on alumina. These clusters have sizes on the order of lO A. while the alumina pore sizes on which the Pi is deposited are on the order of 100 to 10.0(K) A (i.e., 10 to 1000 nm). 

Two electrodes are of importance, platinized Pt and Hg. Electrons transfer easiest from a platinized Pt electrode, so this type is preferred for cathodes. Hg resists the transfer of electrons and is preferred for metals more negative than H , because it reduces the hydrogen evolution so reductions can take place. This electrode is preferred for many electrochemical reactions. To platinize a Pt electrode, simply deposit a thin film of Pt on it, usually from a dilute chloroplatinic acid solution. 

Pt/Al-B catalyst was made by reducing by gaseous hydrogen (4% in Ar) at 300°C a catalyst precursor that was obtained by incipiently wetting Al-B by chloroplatinic acid solution. The bimetallic Pt-Ru catalysts were prepared on Al-B by co-impregnation of the metal salts followed by the chemical reduction (method-1) at the same temperatures that were used for the monometallic catalysts, as described briefly above. 

A shiny Pt foil was platinized by passing a 30 mA current for 10 min through a 7 X 10 M chloroplatinic acid solution containing 6 X 10 M lead acetate. A layer of polycrystalline chlorophyll, containing 1.5 X 10 Chi a molecules, was deposited on the platinized electrode surface, using the procedure described by Tang and Albrecht (6). The Chi a-plated electrode then was platinized again in the same chloroplatinic acid solution, except that the 30 mA current was passed for only 15 seconds. 

Platinum electrodes may be coated with platimun black ( platinized ) to increase the surface area and sensitivity. This finely divided form of platimun is prepared by electrolysis in a chloroplatinic acid solution containing a small amount of lead acetate. Platinization of platinum cells is not recommended on cells for measurements below lOpScm", although a trace of platinum black is sometimes suggested in these regions. 

Egli WA, Visintin A, Triaca WE, Arvia AJ. The development of faceting and roughening at platinum pol5rfaceted single-crystal electrodes in a chloroplatinic acid solution. Appl Surf Sci 1993 68 583-93. 

To a polymerization vial is added 20 gm of I, 5 gm of II, and 2.5 gm of III. A trace of chloroplatinic acid solution is added, and the mixture is evacuated to remove bubbles and cured to give a clear solid rubber. 

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