Zirconium phosphate particles are synthesized by providing a solution of
zirconium oxychloride in an aqueous solvent, adding at least one
oxygen-containing additive to the solution, the oxygen-containing
additive being selected to form a complex with zirconium ions in the
solution of zirconium oxychloride and thereby reduce hydration of the
zirconium ions, and combining this solution with phosphoric acid or a
phosphoric acid salt to obtain zirconium phosphate particles by sol gel
precipitation.