STUDY OF THE STATE OF TRANSITION-METAL CATIONS ON THE SURFACE OF CATALYSTS BY IR SPECTROSCOPY USING ADSORBED PROBE-MOLECULES (CO, NO) .12. INFLUENCE OF MODIFYING ADDITIVES OF ZIRCONIUM AND CESIUM OXIDES ON THESTATE OF SUPPORTED COPPER

The electronic state of copper atoms and ions in the supported copper- alumina catalysts modified with zirconium and cesium oxides is studied by IR spectroscopy using adsorption of CO. The ZrO2 additives are sho wn to increase the dispersion of the supported metal, stabilize the io nic states of copper, add improve their resistance to reduction with H -2 The Cs2O additives decrease the effective charge of the copper ions and facilitate their fast reduction in the presence of CO and H-2. Th e effects observed are caused by the variation of the metal-support in teraction and the electronic donor-acceptor interaction of copper atom s and ions with the modifying oxide.