A series of samples in Cu-Cr-O composite oxide system were synthesized by citratecomplexation method. The catalytic activities of samples were evaluated using CO oxidation astest reaction, and structural imperfection was determined by XRD analysis. The results indicatethat two phases coexisting under the preparative conditions result in structural imperfection of thesamples, which leads to enhanced activities of Cu-Cr-O composite oxides. The catalytic activityfor CO oxidation reaction increases with Cu3+ contents in the samples.
