Two different titanias were used as supports for MoS2 catalysts, Degus
sa P25 titania and a microroughened titania prepared in our laboratory
. The Mo weight loading was varied to study the effect of loading on t
he pyridine hydrodenitrogenation activity. It was found that the speci
fic activity of sulfided molybdena on the P25 titania decreased monoto
nically with increasing loading. On the other hand, the microroughened
titania did not show such a fall off in activity; furthermore its spe
cific activity was over an order of magnitude greater than that of the
P25-supported sample. The rather surprising behavior of MoS2 supporte
d on microroughened titania can be related to the structure of the cat
alyst. On the microroughened titania, the MoS2 sheets are curved with
radii of curvature ranging from 2-5 mm. These strained MoS2 layers cou
ld lead to the formation of unique catalytically active sites in the b
asal plane of MoS2, not otherwise obtained on conventional supports. (
C) 1996 Academic Press, Inc.