Gas phase analysis of CO interactions with solid surfaces at high temperatures

An in situ method including mass spectrometry and labeled gases is presented and used to gain information on adsorption of molecules at high temperatures (>300 8C). Isotopic exchange rate in H2 upon exposure to an oxidized zicaloy-2 sample and exchange rate in CO upon exposure to various materials have been measured. From these measurements, molecular dissociation rates in respective system have been calculated. The influence of CO and N2 on the uptake rate of H2 in zirconium and oxidized zicaloy-2 is discussed in terms of tendency for adsorption at high temperatures. In the case of oxidized Cr exposed to CO gas with 12C, 13C, 16O and 18O, the influence of H2O is investigated with respect to dissociation of CO molecules. The presented data supports a view of different tendencies for molecular adsorption of H2O, CO, N2, and H2 molecules on surfaces at high temperatures. # 2004 Elsevier B.V. All rights reserved.