Visualizing H2O Molecules Reacting at TiO2 Surface with TEM

Session

PSA.5 - Nanoparticles & Catalysts

Authors

Prof. Yong Wang (1)

Affiliations

1. Zhejiang University

Keywords

Environmental TEM; TiO2; Water reaction

Abstract text

The advance of catalytic science and technology relies on the atomistic understanding of the reaction mechanism. It involves the identification of where and how the reactants adsorb on the surface, whether they react there, and what the intermediates are. In the past decades, significant progress has been achieved in characterizing the adsorption of molecules by scanning tunneling microscopy, or deducing the active sites through monitoring the variation of spectroscopy during the reaction. The most ideal way for understanding catalysis is, however, to “see” the reaction taking place at the molecular level. In this work, by employing anatase TiO₂ (1×4)-(001) surface as catalyst, which provides highly ordered Ti4c “active rows”, we realized real-time monitoring of H₂O molecule dissociating and reacting on the catalyst surface by in-situ environmental transmission electron microscopy [1-4]. The unique “twin-protrusion” configuration of adsorbed H₂O was discovered (Fig. 1), which was visualized to react with CO on these active rows at the molecular level [1]. This work demonstrates that the in situ ETEM is capable to monitor the catalytic process taking place at highly ordered active sites.

 

Fig. 1 Adsorbed H₂O species on TiO₂ (001) surface (scale bar: 1nm)

References

[1] W Yuan et al Science 367 (2020) 428.

[2] W Yuan et al Nano Lett. 16 (2016) 132

[3] W Yuan et al Chem. Mater. 29 (2017) 3189

[4] W Yuan et al Chem. Mater. 30 (2018) 288