1999 heterogeneous catalysis, catalysts

heterogeneous catalysis, catalystsH 2000

48 - 019Thermal Stability of Sol–Gel-Derived Porous AM-AlxZr MixedOxides. — Nearly domain-free, amorphous Al2O3–ZrO2 mixed oxidescovering the whole composition range are prepared by a modified sol–gelprocess. The materials exhibit a high porosity, especially those with high Alcontent have surface areas of up to 600 m2/g. The samples with low zirconiacontent (0–20 wt.%) are thermally stable up to 750 ◦C and have surface areasof 180–260 m2/g. Surface areas of ≈80 m2/g are maintained after treatment at1000 ◦C. The incorporation of a variety of common metal ions does not resultin the expected thermal stabilization. However, by subsequent impregnation ofthe materials with Si(O-Et)4, surface areas up to 200 m2/g are maintained evenafter treatment at 1250 ◦C. — (KLEIN, JENS; MAIER, WILHELM F.; Chem.Mater. 11 (1999) 9, 2584-2593; MPI Kohlenforsch., D-45470 Muelheim/Ruhr,Germany; EN)

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