High surface area silicon carbide doped with zirconium for use as catalystsupport. Preparation, characterization and catalytic application

Zirconium doped SiC with a surface area from 88 to 200 m(2) g(-1) was synth esized using the shape memory concept method followed by calcination in air at a temperature of less than or equal to 480 degrees C. The material obta ined was composed of beta-SiC and small ZrO2 particles dispersed throughout the material matrix and a significant amount of an amorphous phase contain ing Si, Zr and O, Molybdenum oxycarbide, the active isomerization phase, su pported on such a material displayed a similar behavior to that obtained on pure SiC for the n-heptane isomerization reaction. A comparison made with the molybdenum oxycarbide catalyst supported on pure ZrO2 showed that the Z r doped SiC was not simply made of silicon carbide coated with a layer of Z rO2 on the surface but probably an amorphous phase containing Si, Zr and O which displays a similar behavior as pure SiC. (C) 1999 Elsevier Science B. V. All rights reserved.