Study of the nature and properties of surface centers of a Ni-Cr oxide catalyst according to ir spectra of adsorbed CO and NH3 probe molecules

The modification of a Ni-Cr oxide catalyst during reduction was studied by IR spectroscopy of adsorbed CO and NH₃ probe molecules. It was determined that in the starting oxidized sample the nickel cations were in the form of oxide clusters distributed over the surface of chromium oxide. As a result of reduction, they were depleted in oxygen, and metal clusters were formed and enlarged. Effective oxidation, by water vapor, of part of the surface of the metallic-nickel clusters that formed during reduction was observed.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2718–2725, December, 1991.