HYDRODECHLORINATION OF CCL2FCCLF2 OVER NIO-CR2O3 CATALYSTS

The vapor-phase hydrodechlorination of CCl2FCClF2 CCl2FCClF2 + H-2 --> ClFC=CF2 + HFC=CF2 + HCl is promoted at around 400-degrees-C by NiO-Cr2O3, especially by a mixture containing 70 at% of Cr. The catalytic activity of the mixed oxide is well maintained, and nearly 100% conversion was observed even after a running time of 5.25 h. However, the reaction was not promoted by Cr2O3 alone, and CH4 formation and deactivation due to carbonaceous deposit on the surface were markedly promoted by NiO and NiO-Cr2O3 containing smaller amounts of Cr2O3. By reference to the results of XRD and XPS measurements, the excellent catalytic behavior of NiO-Cr2O3 (Cr content: 70 at%) was attributed to NiCr2O4 being dispersed by Cr2O3 on the surface.