THE ISOMERIZATION OF CYCLOPROPANE OVER REDUCED MOLYBDENA-ALUMINA CATALYSTS

The isomerization and metathesis of cyclopropane were carried out over a series of reduced molybdena-alumina catalysts (1.7-13 wt% Mo). The distribution of Mo oxidation states was determined by XPS, The average Mo oxidation state estimated from XPS agreed with that obtained by me asuring the O-2 consumption on reoxidation for a given catalyst. A goo d correlation was found between the catalytic activity for the isomeri zation reaction and the relative intensity of the XPS peak attributed to paired double-bonded Mo (TV) species (as in MoO2), The results indi cate a direct relationship between these Mo (IV) species and the coord inative unsaturated sites involved in the formation of metallocyclobut ane. The latter is reportedly the intermediate required for the isomer ization reaction to take place. (C) 1997 Academic Press.