Synthesis of cerium orthophosphates with monazite and rhabdophane structure from phosphoric acid solutions in the presence of hydrogen peroxide

It has been proposed to conduct the synthesis of cerium(III) orthophosphates by reacting cerium(IV) compounds with hydrogen peroxide in the presence of concentrated orthophosphoric acid at ambient temperature. It has been shown that the reaction of H2O2 with CeO2 suspensions in H3PO4 medium produces CePO4 · xH2O (rhabdophane structure), while that with CeO2 solutions in concentrated H3PO4 results in CePO4 (monazite structure).