Preparation of Microporous Rare-earth Oxyhalides.
U S Pat 3 922 331 1975 Nov; :
Microporous rare-earth oxyhalides are prepared by reacting a rare- earth halide with an alkylene oxide in a polar solvent at room temperature. The precipitate or gel formed by the reaction, after being dried in an air stream at not over 600 deg c, is a rare-earth oxyhalide consisting of a microporous solid. The materials are suitable for use as heterogeneous catalysts, adsorbents, or phosphors in the form of rare-earth oxyhalides. For example, dysprosium oxychloride was prepared by mixing 63.8 G of dycl3.6H2o with 169 ml methyl alcohol. The mixture was centrifuged and 150 ml of clear supernatant was recovered. The mixture was centrifuged to remove insoluble impurities present in commercially obtained rare- earth halides. The recovered supernatant was then mixed with 210 ml of 3m propylene oxide in methyl alcohol at room temperature. Within 1.5 H a stiff yellow gel formed. This gel was air dried and rinsed with ether. The product then was heated under vacuum at 600 deg c for 16 h. After roasting at 600 deg c under a flow of air for 16 h the material became light yellow and contained 14.3 pct cl, the composition corresponding to 86 pct dyocl and the remainder dy2o3.
U.S. Pat. 3,922,331; Nov. 25, 1975; Chem. Abstr. 81:P123,766j