Abstract
The coordination of H2 to a metal center via polarization of its σ bond electron density, known as a Kubas complex, is the means by which H2 chemisorbs at Ru4+ sites on the rutile RuO2(110) surface. This distortion of electron density off an interatomic axis is often described as a 'banana-bond.' We show that the Ru-H2 banana-bond can be destabilized and split using visible light. Photodesorption of H2 (or D2) is evident by mass spectrometry and scanning tunneling microscopy. From time-dependent density functional theory, the key optical excitation splitting the Ru-H2 complex involves an interband transition in RuO2 which effectively diminishes its Lewis acidity, thereby weakening the Kubas complex. Such excitations are not expected to affect adsorbates on RuO2 given its metallic properties. Therefore, this common thermal cocatalyst employed in photocatalysis is, itself, photoactive.
Original language | English |
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Pages (from-to) | 8714-8717 |
Number of pages | 4 |
Journal | Journal of the American Chemical Society |
Volume | 138 |
Issue number | 28 |
DOIs | |
State | Published - Jul 20 2016 |
Externally published | Yes |
Funding
This work was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences and Biosciences and performed in EMSL, a national scientific user facility sponsored by the Department of Energys Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory (PNNL). PNNL is a multiprogram national laboratory operated for DOE by Battelle.