Adsorption and photodesorption of weakly-bound carbon monoxide, CO, from reduced and hydroxylated rutile TiO2(110) (r- and h- TiO2(110)) at sub-monolayer coverages is studied with atomically-resolved scanning tunneling microscopy (STM) along with ensemble-averaged temperature-programmed desorption (TPD) and angle-resolved photon-stimulated desorption (PSD) at low temperatures ( 50 K). STM data weighted by the concentration of each kind of adsorption sites on r-TiO2(110) give an adsorption probability which is the highest for the bridging oxygen vacancies (VO) and very low for the Ti5c sites closest to VO. Occupancy of the remaining Ti5c sites with CO is significant, but smaller than for VO. The probability distribution for the different adsorption sites corresponds to a very small difference in CO adsorption energies:
Revised: December 15, 2017 |
Published: September 21, 2017
Citation
Mu R., A.P. Dahal, Z. Wang, Z. Dohnalek, G.A. Kimmel, N.G. Petrik, and I.V. Lyubinetsky. 2017.Adsorption and Photodesorption of CO from Charged Point-Defects on TiO2(110).The Journal of Physical Chemistry Letters 8, no. 18:4565-4572.PNNL-SA-128233.doi:10.1021/acs.jpclett.7b02052