Effect of the potassium promoter content in V2O5/TiO2 catalysts on their physicochemical and catalytic properties in oxidative dehydrogenation of propane

To optimize the content of the potassium promoter in V2O5/TiO2 system for o xidative dehydrogenation of propane ODH, the vanadia-titania catalysts of t he potassium/vanadium (K/V) ratio ranging from 0.01 to 0.2 were obtained an d tested in the title reaction. It has been found that the total rate of th e propane consumption decreases considerably already on addition of small a mounts of K (K/V = 0.01) to vanadia-titania system and only slightly at hig her K content: its value is constant beginning from K/V = 0.05. The distinc t increase in the selectivity to propene on addition of K is, on the other hand, observed at higher K content (K/V = 0.05-0.1). Addition of K to vanad ia-titania catalysts leads to the decrease in acidity and increase in basic ity of the system, as shown by measurements of the isopropanol decompositio n, a probe reaction of acido-basic properties.