The transport of H adatoms across oxide supports plays an important role in many catalytic reactions. We investigate the dynamics of H/Fe3O4(001) between 295 and 382 K. By scanning tunneling microscopy at frame rates of up to 19.6 fps, we observe the thermally activated switching of H between two O atoms on neighboring Fe rows. This switching rate changes in proximity to a defect, explained by density functional theory as a distortion in the Fe-O lattice shortening the diffusion path. Quantitative analysis yields an apparent activation barrier of 0.94 ± 0.07 eV on a pristine surface. The present work highlights the importance of local techniques in the study of atomic-scale dynamics at defective surfaces such as oxide supports.
Bourgund A., Lechner B.A.J., Meier M., Franchini C., Parkinson G.S., Heiz U., et al. (2019). Influence of Local Defects on the Dynamics of O-H Bond Breaking and Formation on a Magnetite Surface. JOURNAL OF PHYSICAL CHEMISTRY. C, 123(32), 19742-19747 [10.1021/acs.jpcc.9b05547].
Influence of Local Defects on the Dynamics of O-H Bond Breaking and Formation on a Magnetite Surface
Franchini C.Membro del Collaboration Group
;
2019
Abstract
The transport of H adatoms across oxide supports plays an important role in many catalytic reactions. We investigate the dynamics of H/Fe3O4(001) between 295 and 382 K. By scanning tunneling microscopy at frame rates of up to 19.6 fps, we observe the thermally activated switching of H between two O atoms on neighboring Fe rows. This switching rate changes in proximity to a defect, explained by density functional theory as a distortion in the Fe-O lattice shortening the diffusion path. Quantitative analysis yields an apparent activation barrier of 0.94 ± 0.07 eV on a pristine surface. The present work highlights the importance of local techniques in the study of atomic-scale dynamics at defective surfaces such as oxide supports.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
