FORMATION OF NANO-AND ULTRAFINE PALLADIUM POWDERS IN THE PRESENCE OF «RED-OX»SYSTEM«TITANIUM (III) - TITANIUM (IV)»

Аннотация

The results of studies on the processes of obtaining ultra - and nanodispersed palladium powders from
sulphate solutions by a combined chemical and electrochemical method in the presence of a "red-ox" system of
titanium (III) - titanium (IV) are presented. It has been shown that when a titanium trivalent sulphate solution is
added to a solution containing palladium (II) ions, palladium ions are immediately reduced to elemental state to form
a nanodispersed powder. The completeness of the above-mentioned oxidizing-reducing reactions is established on
the basis of calculating the equilibrium constant (K), which is 1034 and indicates that trivalent titanium ions
completely reduce palladium ions to elemental state.
Effect of initial concentration of palladium ions on amount of formed palladium powder with addition of
equivalent amount of trivalent titanium ions is investigated.
According to the authors, upon reduction of palladium ions, elemental palladium is formed in the atomic state,
and over time, the atoms begin to combine with each other. Subsequently, atomic particles are combined into
colloidal particles. It has been found that in the absence of coagulants, the colloidal palladium solution is stable for 2-
3 hours, and in the presence of gelatin, the stability increases and remains for 36 hours.
It was shown that in all experiments powders with spherical particles are formed, the average sizes of which
range from 0.116-0.240 microns.
Based on the results of the presented studies, a new technology for producing ultra - and nano-sized palladium
powders is proposed.