Temperature-programmed desorption study of NO reactions on rutile TiO₂(110)-1×1

Journal Article · 23 February 2016 · Surface Science

DOI: https://doi.org/10.1016/j.susc.2016.01.032 · OSTI ID:1250888

Kim, Boseong ^[1]; Dohnalek, Zdenek ^[2]; Szanyi, Janos ^[2]; Kay, Bruce D. ^[2]; Kim, Yu Kwon  ^[1]

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1. Ajou Univ., Suwon (South Korea)
2. Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

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 product 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.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
• Sponsoring Organization: USDOE; USDOE Office of Science (SC), Basic Energy Sciences (BES); USDOE Office of Science (SC), Biological and Environmental Research (BER)
• OSTI ID: 1250888
• Report Number(s): PNNL-SA-114302; PII: S0039602816000881
• Journal Information: Surface Science, Journal Name: Surface Science Journal Issue: C Vol. 117; ISSN 0039-6028
• Publisher: ElsevierCopyright Statement
• Country of Publication: United States
• Language: English