Atomic-Scale View on the H2O Formation Reaction from H2 on O-Rich RuO2(110)

详细信息    查看全文

• 作者：Yinying Wei ; Umberto Martinez ; Lutz Lammich ; Flemming Besenbacher ; Stefan Wendt
• 刊名：Journal of Physical Chemistry C
• 出版年：2014
• 出版时间：December 4, 2014
• 年：2014
• 卷：118
• 期：48
• 页码：27989-27997
• 全文大小：567K
• ISSN：1932-7455

文摘

The H₂O formation reaction from H₂ on O-rich RuO₂(110) was studied by temperature-programmed desorption and reaction (TPD/TPR) and scanning tunneling microscopy (STM) measurements and density functional theory (DFT) calculations. On the one hand, following H2 adsorption at 270 K, our TPD/TPR measurements reveal that the on-top O species (O_ot) enhances the sticking probability of H₂, thus facilitating the H₂ adsorption and dissociation on O-rich RuO₂(110). On the other hand, for low H₂ adsorption temperature (170 K), the limited mobility of H_ad species hinders H₂ adsorption at a high coverage of preadsorbed O_ot. To better understand the strong influence of the adsorption temperature and the interplay between coadsorbed species, we conducted DFT calculations and high-resolution STM measurements. Two distinct adsorbate configurations, H_ad鈥揙_ot and O_ot鈥揌_ad鈥揙_ot, are identified by STM. Mechanisms and molecular models for H₂ dissociation and H_ad diffusion on O-rich RuO₂(110) are proposed.