Alumina-supported vanadium oxide in the dehydrogenation of butanes

The activity of an alumina-supported vanadium oxide catalyst was studied in the dehydrogenation of i-butane and n-butane at 580 degrees C under atmosp heric pressure. The dehydrogenation reaction of the butanes to butenes and hydrogen was found to be catalysed by the reduced state of vanadium oxide ( V4+ Or V3+, Or possibly both). The activity of the catalyst was therefore s tudied in detail after reduction with H-2, CH4, and CO. The activity was hi ghest after CO reduction, even though the average oxidation states after th e three reductions were similar. It was concluded that the main reason for the lower activity after H-2 and CH4 reduction was the formation of OH grou ps that decreased the number of active sites for the dehydrogenation reacti on. The primary cause of the catalyst deactivation during dehydrogenation w as the formation of cake. (C) 2000 Academic Press.