Am. Donia et al., Preparation of mixed Co and Cu oxides via thermal decomposition of their oxalates, and study of their catalytic properties, J THERM ANA, 61(1), 2000, pp. 249-261
Mixed oxides were prepared by the thermal decomposition of the oxalates of
cobalt(II) and copper(II) coprecipitated from aqueous solution or made by m
echanical mixing. The compositions and structures of the oxides were confir
med by means of TG and X-ray powder diffraction spectroscopy. The catalytic
behaviour of the oxides obtained was studied by using the decomposition of
H2O2 as a model reaction. The results were compared with those on the oxid
es produced from the thermal decomposition of mechanically mixed oxalates.
The catalytic activities of the mixed oxides were found to be lower than th
at of pure cobalt oxide, but higher than that of copper oxide. This result
was interpreted in terms of the relative standard reduction potential of th
e catalyst as compared with that of H2O2. The catalytic activity of the mix
ed oxides obtained from the coprecipitate was found to be lower than that o
f the oxides obtained from the mechanical mixture at the same temperature.
As the temperature of preparation was increased, the catalytic activities o
f the oxides obtained decreased. This was attributed to the solid-solid int
eractions, which gave a new phase with lower catalytic activity than those
of the interacting phases.