ESR AND DRES STUDY OF THE STATE OF COBALT, NICKEL, AND COPPER IN OXIDE CATALYSTS OBTAINED FROM ACTIVATED ALUMINUM-ALLOYS

ESR and DRES were used to study the state of the cobalt, nickel, and c opper ions in catalysts obtained by dissolving cobalt-, nickel-, and/o r copper-containing activated aluminum alloys in water with subsequent roasting or impregnation of the support obtained by dissolving activa ted aluminum in water and solutions of Co, Ni, or Cu nitrates. The for mation of highly dispersed M0 aggregates, which are rather readily oxi dized, is characteristic before heat treatment for Co- and Ni-containi ng catalysts obtained from the alloys. In the case of Cu-containing sy stems, several types of copper ions are observed independently of the method of synthesis even before heat treatment. Heat treatment leads t o the aggregation of oxidized Co2, ions to give highly dispersed oxide phases. The roasted nickel and copper catalysts contain several types of nickel and copper ions, respectively.