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

TY - JOUR

T1 - Atomic-Scale View on the H2O Formation Reaction from H2 on O-Rich RuO2(110)

AU - Wei, Yinying

AU - Martinez, Umberto

AU - Lammich, Lutz

AU - Besenbacher, Flemming

AU - Wendt, Stefan

PY - 2014/11

Y1 - 2014/11

N2 - The H2O formation reaction from H-2 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 H-2 adsorption at 270 K, our TPD/TPR measurements reveal that the on-top O species (Oot) enhances the sticking probability of H-2, thus facilitating the H-2 adsorption and dissociation on O-rich RuO2(110). On the other hand, for low H-2 adsorption temperature (170 K), the limited mobility of Had species hinders H-2 adsorption at a high coverage of preadsorbed Oot. 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, Had-Oot and Oot-Had-Oot, are identified by STM. Mechanisms and molecular models for H-2 dissociation and Had diffusion on O-rich RuO2(110) are proposed.

AB - The H2O formation reaction from H-2 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 H-2 adsorption at 270 K, our TPD/TPR measurements reveal that the on-top O species (Oot) enhances the sticking probability of H-2, thus facilitating the H-2 adsorption and dissociation on O-rich RuO2(110). On the other hand, for low H-2 adsorption temperature (170 K), the limited mobility of Had species hinders H-2 adsorption at a high coverage of preadsorbed Oot. 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, Had-Oot and Oot-Had-Oot, are identified by STM. Mechanisms and molecular models for H-2 dissociation and Had diffusion on O-rich RuO2(110) are proposed.

KW - SCANNING-TUNNELING-MICROSCOPY; SURFACE-CHEMISTRY; RUTHENIUM DIOXIDE

KW - RuO2(110)

KW - PHOTOCATALYSIS

KW - HYDROGEN

KW - OXYGEN

KW - water formation

KW - OXIDE SURFACE

U2 - 10.1021/jp509510j

DO - 10.1021/jp509510j

M3 - Journal article

SN - 1932-7447

VL - 118

SP - 27989

EP - 27997

JO - The Journal of Physical Chemistry Part C

JF - The Journal of Physical Chemistry Part C

IS - 48

ER -