Adsorption, Desorption, and Displacement Kinetics of H2O and CO2 on TiO2(110)

Journal Article · Thu Jul 17 04:00:00 EDT 2014 · Journal of Physical Chemistry B, 118(28):8054-8061

DOI:https://doi.org/10.1021/jp501131v· OSTI ID:1171304

Smith, R. Scott; Li, Zhenjun; Chen, Long; Dohnalek, Zdenek; Kay, Bruce D.

The adsorption, desorption, and displacement kinetics of H2O and CO2 on TiO2(110) are investigated using temperature programmed desorption (TPD) and molecular beam techniques. The TPD spectra for both H2O and CO2 have well-resolved peaks corresponding to desorption from bridge-bonded oxygen (BBO), Ti, and oxygen vacancies (VO) sites in order of increasing peak temperature. Analysis of the saturated monolayer peak for both species reveals that the corresponding adsorption energies on all sites are greater for H2O and for CO2. Sequential dosing of H2O and CO2 reveals that, independent of the dose order, H2O molecules will displace CO2 in order to occupy the highest energy binding sites available. Isothermal experiments show that the displacement of CO2 by H2O occurs between 75 and 80 K. Further analysis shows that a ratio of 4 H2O to 3 CO2 molecules is needed to displace CO2 from the TiO2(110) surface.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1171304
• Report Number(s): PNNL-SA-100691; 48154; KC0301020
• Journal Information: Journal of Physical Chemistry B, 118(28):8054-8061, Journal Name: Journal of Physical Chemistry B, 118(28):8054-8061
• Country of Publication: United States
• Language: English

Related Subjects

Environmental Molecular Sciences Laboratory