TEMPERATURE AND HYDROCARBON PARTIAL-PRESS URE EFFECT ON THE ISOMERIZATION OF N-HEXANE ON MOLYBDENUM OXYCARBIDE CATALYST

The study of n-hexane isomerization on MoO3 shows the formation of a n ew catalytically active phase, a molybdenum oxycarbide, which exhibits a stable activity and isomer selectivity with time on stream. The stu dy as a function of the reaction temperature shows that a too low temp erature does not allows the MoO3 transformation, while a too high temp erature prevents the development of the MoOxCy phase to the benefit of a surface carbide phase. For variable n-hexane partial pressure, one can observe the same trend with the apparition of surface carbone and carbide species with higher partial pressures, which are not interesti ng for the isomerization.