Formation of PuSiO4 under hydrothermal conditions

Attempts to synthesize plutonium (IV) silicate, PuSiO₄, have been performed on the basis of the results recently reported in the literature for CeSiO₄, ThSiO₄ and USiO₄ under hydrothermal conditions. Although it was not possible to prepare PuSiO₄ by applying the conditions reported for thorium and uranium, an efficient way of PuSiO₄ synthesis was established following those optimized for CeSiO₄ system. This method was based on the slow oxidation of plutonium (III) silicate reactants under hydrothermal conditions at 150°C in hydrochloric acid (pH = 3 – 4). This result shed a new light on the potential behavior of plutonium in reductive environment, highlighted the representativeness of cerium surrogates to study plutonium in such conditions and brought some important pieces of information on plutonium chemistry in silicate solutions.