Specifics of reactions of cerium sulfate and europium sulfate with hydrogen

Abstract

Reactions of cerium sulfate and europium sulfate with hydrogen have been studied. Diagrams showing the evolution of phase composition of the polycrystalline products of reaction between europium sulfate and hydrogen are constructed. The reaction of Ce₂(SO₄)₃ with hydrogen at 600°С consecutively yields Ce₂O₂S and Ce₂O₃ phases. At 800°С the batch is >95 mol % Ce2O3. At 480-500°С, a single-phase sample of EuSO4 is prepared; at 600-1000°С, Eu₂O₂S is prepared; and at 1050°С, the batch is >95 mol % Eu₂O₂S and up to 5 mol % Eu₂O₃. Atomic-force microscopy shows that europium sulfate grains, which represent agglomerates of particles 10-20 μm in size, are degraded upon reaction with hydrogen into individual ovalshaped particles sized 40-60 × 130-200 nm.