Adams catalyst solubility, water

Ammonium chloroplatinate often can be used to advantage in place of chloroplatim c acid in the preparation of Adams catalyst. A mixture of 3 g. of ammonium chloroplatinate and 30 g. of sodium nitrate in a casserole or Pyrex beaker is heated gently at first until the rapid evolution of gas slackens and then more strongly until a temperature of 500° is reached. This operation requires about fifteen minutes and there is no spattering. The temperature is held at 500-520° for one-half hour and the mixture is then allowed to cool. The platinum oxide catalyst, collected in the usual way by extracting the soluble salts with water, weighs 1.5 g. and it is comparable in appearance and in activity to the material prepared from chloroplatinic acid. 

Reetz, M.T. and Koch, M., Water-soluble colloidal Adams catalyst preparation and use in catalysis,... 

Considerably easier is the preparation of aqueous colloidal forms of transition metal oxides, which was optimized with the emergence of a straightforward method. The first example pertains to a water-soluble colloidal form of Adams catalyst (Pt02) [52]. 

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