Visualization of Shallow‐Groove Expansion of Au(111) Facet under Methane Pyrolysis. Issue 23 (6th October 2020)

• Record Type: Journal Article
• Authors: Li, Xiang; Shen, Yongli; Ge, Mengke; Deng, Ziliang; Yuan, Wenjuan; Xi, Wei; Luo, Jun
• Is Part Of: Advanced materials interfaces. Volume 7:Issue 23(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-10-06
• Subjects: Au(111) facet -- in situ transmission electron microscopy -- methane pyrolysis -- nanoporous gold; Materials science -- Periodicals; 620.11
• DOI: 10.1002/admi.202001245
• Languages: English
• ISSNs: 2196-7350

Abstract

Abstract: Metallic catalyst facets are considered pivotal in determining the activity and selectivity of heterogeneous catalysis. However, the characterization of the dynamic evolution of metallic catalyst facets remains unsatisfactory, and the identification of evolved facets relies upon phenomenological criteria. Here, to understand the functional mechanism of catalyst facet formation, the dynamic evolution of the Au(111) facet is investigated by in situ transmission electron microscopy during methane pyrolysis. A shallow groove of a few atoms in depth is formed and expanded on the Au(111) facet. Density functional theory results show that the adsorption of carbon weakens the AuAu bonds, facilitating Au atom removal from the surface. Finally, a new flat Au(111) facet is formed. Thus, the facets undergo dynamic evolution during the actual pyrolytic reaction. This research may promote understanding of the catalytic mechanism and guide the design of the next generation of highly efficient catalysts. Abstract : During methane pyrolysis, Au atoms on the surface of the Au(111) facet are easily removed with the adsorption of C, thereby forming shallow grooves. The formation and expansion of a series of shallow grooves ultimately leads to the formation of a new flat Au(111) facet.