A series of pure and mixed copper and cobalt oxides was prepared by calcination of copper and cobalt nitrate hexahydrate at 500-1000 degreesC. Another series of CuxCo3-xO4 spinel (0.0 less than or equal to x less than or equal to 1.0) was synthesized by the decomposition of nitrate precursors at 350 degreesC. The effect of K2O-doping on the physicochemical properties of the spinel form was investigated. The thermal behavior of the pure and binary solids has been studied using TG, DTG, and DSC analyses. The thermal products were characterized using XRD analysis. The results revealed that, solid-solid interactions take place between anhydrous nitrate precursors and/or oxides to form different forms of copper oxocobaltate. The produced oxocobaltate dissolves the excess of Co3O4 forming solid solution of the formula Cu1-xCoxCo2O4. Both copper and cobalt oxides have mutual thermal effects on each other. The catalytic activities of various prepared mixed solids were tested using the catalytic decomposition of H2O2 in aqueous solution at 30-50 degreesC.