| 摘要 |
A solution containing a hydroxylammonium salt is prepared by catalytically reducing with the aid of molecular hydrogen a nitrate solution which has a pH of from 0-3 obtained by the addition to the solution of either phosphoric acid or a bisulphate. The solution preferably also contains a soluble sulphate or phosphate of such a type and amount that the solution is buffered at said pH. Suitable mixtures are phosphoric acid and ammonium monophosphate and ammonium bisulphate with ammonium sulphate. The catalyst may be palladium, or possibly a noble metal on a carrier, e.g. alumina or activated carbon, and the nitrate concentration is in the molar range 1 to 5. |
