Oxide supported MoS2 catalysts of unusual morphology

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