Solid-State Transformations in Inner Coordination Sphere of Co(NH3)6Fe(C2O4)3∙3H2O as a Route to Access Catalytically Active Co-Fe Materials

摘要

Thermal decomposition of [Co(NH3)6][Fe(C2O4)3]∙3H2O in argon atmosphere, at a low heating rate (3°/min), and in large amounts of the initial complex (~0.1 mole), has been studied. It was possible to distinguish four decomposition steps upon heating: In the temperature range of 50–100 °C—the loss of crystal water; 100–190 °C—stability region of dehydrated complex; 230–270 °C—the range of stability of intermediate phase with the formula CoFe(NH3)2(C2O4)2; 270–350 °C—thermal decomposition of the intermediate with the formation of metallic products and further air oxidation with the formation of Co1.5Fe1.5O4. Catalytic properties of thermolysis products were tested in the decomposition reaction of H2O2 (inactive), oxidation of acetone (average activity), and decomposition of ammonium perchlorate (highly active).