THE ACTIVITY OF MOLYBDENUM AND MOLYBDENUM OXIDE MODEL CATALYSTS FOR OLEFIN METATHESIS

The activity of various molybdenum oxides supported on a molybdenum fo il substrate for the catalysis of propylene metathesis is measured usi ng an isolatable, high-pressure reactor incorporated in an ultra-high vacuum (UHV) chamber which allows samples to be transferred directly f rom vacuum into the catalytic test chamber. MoO(x) samples are prepare d both by oxidation of metallic molybdenum and reduction of molybdenum trioxide. The results suggest that the presence of an oxygen overlaye r on the catalyst inhibits reaction and that the ranking of activity f or metathesis at 870 K using 450 Torr of propylene for oxide samples i s MoO2 > MoO3 > MO where MoO2 is approximately 30 times more active th an molybdenum metal under these conditions.