The interaction among cobalt, molybdenum and silica in CoMo/SiO2 catal
ysts has been investigated in a series of catalysts with the same over
all composition and varying interaction among the components. XRD and
DRIFTS give a rough indication of the phases present, and the formatio
n of CoMoO4 can be easily monitored. The formation of CoMoO4 is observ
ed in most of the catalysts due to the poor interaction between molybd
enum oxide and silica. The presence of other minor, non-crystalline ph
ases must be attested by other methods, such as, TPR and catalytic oxi
dation of carbon monoxide. The presence of ''free'' cobalt can be demo
nstrated by a low temperature peak in TPR. The catalytic oxidation of
CO may function as a useful indicator for the interaction between coba
lt and molybdenum, because the oxidation activity of cobalt species in
corporated in a molybdate lattice (i.e. CoMoO4) is considerably less t
han cobalt oxide.