The reduction and passivation behaviour of low pressure methanol CuO-ZnO-Al2O3-V2O5

catalysts have been studied with thermal analysis technique. along with XRD

IR

SEM and activity evaluation. Results show that the industrial catalyst contains about 25% basic carbonate

which is beneficial for getting better selectivity

activity and stability. Catalysts precalcined at 350℃ will lead to the formation of unfavourable structure. Direct reduction of industrial catalysts at low H2 concentration with high gas flow rate and at low temperature cascade rising rate will give good thermal stability and catalytic activity. It is attributed to the fact that some carbonate and hydroxyl groups are retained in the structure. They are assumed to be the necessary coordination species to form active sites

while the precalcined catalysts have lost most of these functional groups. Catalyst passivated under extremely low O2 concentration (0.01%)can restore its activity almost completely after re-reduction. A mathematical model of reduction kinetics has been set up from the thermo-gravimetric curve.