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Systematic temperature-programmed desorption (TPD) studies of NO adsorption and reactions on rutile TiO2(110)-1×1 surface reveal several distinct reaction channels in a temperature range of 50 – 500 K. NO readily reacts on TiO2(110) to form N2O which desorbs between 50 and 200 K (LT N2O channels), which leaves the TiO2 surface populated with adsorbed oxygen atoms (Oa) as a byproduct of N2O formation. In addition, we observe simultaneous desorption peaks of NO and N2O at 270 K (HT1 N2O) and 400 K (HT2 N2O), respectively, both of which are attributed to reaction-limited processes. No N-derived reaction product desorbs from TiO2(110)more » surface above 500 K or higher, while the surface may be populated with Oa’s and oxidized products such as NO2 and NO3. The adsorbate-free TiO2 surface with oxygen vacancies can be regenerated by prolonged annealing at 850 K or higher. Detailed analysis of the three N2O desorption yields reveals that the surface species for the HT channels are likely to be various forms of NO dimers.« less

In this study, systematic temperature-programmed desorption (TPD) studies of NO adsorption and reactions on rutile TiO₂(110)-1 × 1 surface reveal several distinct reaction channels in a temperature range of 50–500 K. NO readily reacts on TiO₂(110) to form N₂O, which desorbs between 50 and 200 K (LT N₂O channels), which leaves the TiO₂ surface populated with adsorbed oxygen atoms (O_a) as a by-product of N₂O formation. In addition, we observe simultaneous desorption peaks of NO and N₂O at 270 K (HT1 N₂O) and 400 K (HT2 N₂O), respectively, both of which are attributed to reaction-limited processes. No N-derived reaction productmore » desorbs from TiO₂(110) surface above 500 K or higher, while the surface may be populated with Oa's and oxidized products such as NO₂ and NO₃. The adsorbate-free TiO₂ surface with oxygen vacancies can be regenerated by prolonged annealing at 850 K or higher. Detailed analysis of the three N₂O desorption yields reveals that the surface species for the HT channels are likely to be various forms of NO dimers.« less