NO INTERACTION WITH THERMALLY ACTIVATED CAO AND SRO SURFACES

By using temperature-programmed desorption gas analysis, thermal desor ption (TD) of (NO)-O-16 with a small amount of (NO)-O-18 was observed in the temperature range 400-1000 K after (NO)-O-18 adsorption on both CaO and SrO powders at room temperature. TD's of N-2 and (N2O)-O-16 w ith a small amount of (N2O)-O-18 were also observed in the temperature range 400-600 K. Based on IR measurements, NO, (NO)(2) and tentative NO2 (or NO3) species were found after (NO)-O-16 adsorption on CaO powd ers. This suggests that oxygen exchange of (NO)-O-18 with CaO and SrO may occur through NO2- or NO3- intermediates during migrating on the s urfaces involving of a lattice oxygen. N2O desorption may be due decom position of (NO)(2), while exchange process is not clear.