Light Makes a Surface Banana-Bond Split: Photodesorption of Molecular Hydrogen from RuO 2 (110)
The coordination of H2 to a metal center via polarization of its 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 banana-bond involves an interband transition in RuO2 which effectively diminishes its Lewis acidity, and thereby weakening the Kubas complex. Such excitations are not expected to affect adsorbates on RuO2 given its metallic properties. Therefore, this common thermal co-catalyst employed in promoting water splitting is, itself, photo-active in the visible.
- Research Organization:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 1328832
- Report Number(s):
- PNNL-SA-117971; 49642; 48287; KC0302010
- Journal Information:
- Journal of the American Chemical Society, Vol. 138, Issue 28; ISSN 0002-7863
- Publisher:
- American Chemical Society (ACS)
- Country of Publication:
- United States
- Language:
- English
Similar Records
Dynamics, Stability, and Adsorption States of Water on Oxidized RuO 2 (110)
Photooxidation and Photodesorption in the Photochemistry of Isobutene on TiO2(110)