Comparative in Situ DRIFTS-MS Study of¹²CO- and¹³CO-TPR on CuO/CeO₂Catalyst

Abstract

A ceria-supported copper oxide catalyst has been examined with respect to interaction with CO by means of CO-TPR tests employing a DRIFTS cell as reactor. Parallel analysis of isotopic shifts in the DRIFTS spectra obtained upon interaction of the catalysts with either 12CO or 13CO allows unambiguous assignment of the various carbonyl and carbonate-type species formed. The study is complemented by separate examination of the stability of carbonyl species focused to get hints on the nature of CO adsorption centers at the catalyst surface. Joint analysis of gases evolution during the CO-TPR tests and DRIFTS spectra is employed to determine the nature of processes taking place during such tests. Additionally, analysis of the various CO2 isotopes evolving during the course of a TPO run subsequent to 13CO-TPR test is employed to discard the occurrence of CO disproportionation upon interaction of the catalyst with CO up to 400 °C.