Understanding Water Splitting on Model Mixed Metal Oxide Photocatalysts
EMSL Project ID
48287
Abstract
There is a need for new fundamental insights into photocatalytic water splitting particularly how to design catalyst systems that extend the catalytic and photocatalytic functionalities of simple materials (like TiO2) through the use of co-catalysts, dopants (to increase photoabsorptivity), promoters (to increase chemical activity) and tandem systems. RuO2 has been widely used as a co-catalysis supported on TiO2 to promote both water photoreduction and photooxidation. However, the fundamental science of how RuO2 functions as a cocatalyst in these water splitting reactions is not well-understood. It is generally believed that RuO2 does not promote optical absorption or extend the absorptivity of the photocatalyst into previously inaccessible spectral regions, but instead that RuO2 as co-catalyst promotes thermal reactions that do not readily occur on the photocatalyst itself. Nevertheless, the role of RuO2 as a co-catalyst in charge separation and trapping has not been well explored. We propose examining the thermal and photochemical properties of RuO2, as a co-catalyst with TiO2, for water splitting (to H2 and/or O2), as well as the importance or RuO2 as a co-catalyst in H2 (and O2) utilization reactions. In particular, we will explore the photochemistry on supported RiO2 clusters grown on TiO3(110) and extend such studies to model high surface area nanoporous RuO2, TiO2 and mixed RuO2-TiO2 systems. We will employ a variety of state-of-the-art surface science approaches (e.g., STM, TPD, vibrational spectroscopies, electron spectroscopies, etc.) to examine the mechanisms, energetics and surface site dependences for water splitting. The role of RuO2 as a photocatalyst and co-photocatalyst will also be explored using the probe reactions (e.g., O2 photodesorption and photodissociation, trimethyl acetate photodecomposition and methyl radical evolving processes). This research effort will provide deeper insight into not only chemistry and photochemistry of water splitting but also into relationships between catalysts and co-catalysts.
Project Details
Project type
Large-Scale EMSL Research
Start Date
2014-10-01
End Date
2016-09-30
Status
Closed
Released Data Link
Team
Principal Investigator
Co-Investigator(s)
Team Members
Related Publications
Henderson M A,Dahal A P,Dohnalek Z ,Lyubinetsky I V 2016. "Strong temperature dependence in the reactivity of H2 on RuO2(110)" Journal of Physical Chemistry Letters 7(15):2967–2970. 10.1021/acs.jpclett.6b01307
Henderson MA, R Mu, AP Dahal, I Lyubinetsky, Z Dohnalek, VA Glezakou, and RJ Rousseau. 2016. "Light makes a banana-bond split: Photodesorption of molecular hydrogen from RuO2(110)." Journal of the American Chemical Society 138(28):8714-8717. doi:10. 1021/jacs. 6b05083
Henderson M A,Shen M 2017. "Electron-scavenging chemistry of benzoquinone on TiO2(110)" Topics in Catalysis 60(6-7):440–445. 10.1007/s11244-016-0707-7
Kim B., Z. Dohnalek, J. Szanyi, B.D. Kay, and Y. Kim. 2016. "Temperature-programmed Desorption Study of NO Reactions on Rutile TiO2(110)-1×1." Surface Science 652. PNNL-SA-114302. doi:10.1016/j.susc.2016.01.032
Petrik NG, and GA Kimmel. 2014. "Probing the photochemistry of chemisorbed oxygen on TiO2(110) with Kr and other co-adsorbates." Physical Chemistry Chemical Physics. PCCP 16(6):2338-2346. doi:10.1039/c3cp54195a
Petrik N.G., G.A. Kimmel, M. Shen, and M.A. Henderson. 2016. "Quenching of Electron Transfer Reactions through Coadsorption: A Study of Oxygen Photodesorption from TiO2(110)." Surface Science 652. PNNL-SA-114433. doi:10.1016/j.susc.2015.12.038
Xu C., M. Lee, Y. Wang, D. Cantu Cantu, J. Li, V. Glezakou, and R.J. Rousseau. 2017. "Structural Rearrangement of Au-Pd Nanoparticles Under Reactions Conditions: An Ab Initio Molecular Dynamics Study." ACS Nano 11, no. 2:1649-1658. PNNL-SA-122190. doi:10.1021/acsnano.6b07409
Xu C, MS Lee, Y Wang, D Cantu Cantu, J Li, VA Glezakou, and RJ Rousseau. 2016. "Structural Rearrangement of Au-Pd Nanoparticles Under Reactions Conditions: An Ab Initio Molecular Dynamics Study." PNNL-SA-122190, Pacific Northwest National Laboratory, Richland, WA. [Unpublished]
Yoon Y, Y Du, JC Garcia, Z Zhu, Z Wang, NG Petrik, GA Kimmel, Z Dohnalek, MA Henderson, RJ Rousseau, NA Deskins, and I Lyubinetsky. 2015. "Anticorrelation between Surface and Subsurface Point Defects and the Impact on the Redox Chemistry of TiO2(110)." Chemphyschem 16(2):313-321. doi:10.1002/cphc.201402599
Yu X, Z Zhang, C Yang, F Bebensee, S Heibler, A Nefedov, M Tang, Q Ge, L Chen, BD Kay, Z Dohnalek, Y Wang, and C Woll. 2016. "Interaction of Formaldehyde with the Rutile TiO2(110) Surface: A Combined Experimental and Theoretical Study." Journal of Physical Chemistry C 120(23):12626-12636. doi:10. 1021/acs. jpcc. 6b03689