A Comparison of CO Oxidation by Hydroxyl and Atomic Oxygen from Water on Low-Coordinated Au Atoms

作者：van Spronsen Matthijs A^*; Weststrate Kees Jan; Juurlink Ludo B F

来源：ACS Catalysis, 2016, 6(10): 7051-7058.

DOI：10.1021/acscatal.6b01720

• fragmentation of water
• CO oxidation
• electron irradiation
• hydroxide
• Au model catalyst
• low-coordinated atoms

The catalytic oxidation of CO is studied at low coordinated Au atoms using a single-crystal approach. Electron irradiation activates an otherwise unreactive overlayer of undissociated D2O on Au(310). A low-coverage D2O/O mixture is subsequently allowed to react at surface temperatures from 105 K upward, with CO supplied from the gas phase. X-ray photoelectron spectroscopy shows the absence of Au oxides and quantifies various O-containing species during the reaction. The dependency of the reaction rate on the surface temperature yields an activation energy for the Langmuir-Hinshelwood reaction of O(ads) and CO(ads) between 26 +/- 4 and 42 +/- 5 kJ/mol. The presented results provide evidence that O(ads) and not OH(ads) is the active reactant on small Au nanoparticles. In addition, the observations suggest that water has a negative effect on the reactivity of O(ads).

• 出版日期2016-10