Atomic Scale Stability of Tungsten-Cobalt Intermetallic Nanocrystals in Reactive Environment at High Temperature

Feng Yang; Haofei Zhao; Xiaowei Wang; Xu Liu; Qidong Liu; Xiyan Liu; Chuanhong Jin; Rongming Wang; Yan Li

doi:10.1021/jacs.9b00473

Atomic Scale Stability of Tungsten-Cobalt Intermetallic Nanocrystals in Reactive Environment at High Temperature

J Am Chem Soc. 2019 Apr 10;141(14):5871-5879. doi: 10.1021/jacs.9b00473. Epub 2019 Mar 28.

Authors

Feng Yang¹, Haofei Zhao², Xiaowei Wang³, Xu Liu¹, Qidong Liu¹, Xiyan Liu¹, Chuanhong Jin³, Rongming Wang², Yan Li¹

Affiliations

¹ Beijing National Laboratory for Molecular Science, Key Laboratory for the Physics and Chemistry of Nanodevices, State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering , Peking University , Beijing 100871 , China.
² Beijing Key Laboratory for Magneto-Photoelectrical Composite and Interface Science, School of Mathematics and Physics , University of Science and Technology Beijing , Beijing 100083 , China.
³ State Key Laboratory of Silicon Materials, School of Materials Science and Engineering , Zhejiang University , Hangzhou 310027 , China.

PMID: 30875209
DOI: 10.1021/jacs.9b00473

Abstract

Catalyst design plays vital roles in structurally relevant reactions. Revealing the catalyst structure and chemistry in the reactive environment at the atomic scale is imperative for the rational design of catalysts as well as the investigation of reaction mechanisms, while in situ characterization at the atomic scale at high temperature is still a great challenge. Here, tracking intermetallic Co₇W₆ nanocrystals with a defined structure and a high melting point by environmental aberration-corrected transmission electron microscopy in combination with in situ synchrotron X-ray absorption spectroscopy, we directly present the structural and chemical stability of the Co₇W₆ nanocrystals in methane, carbon monoxide, and hydrogen at temperatures of 700-1100 °C. The evidence is in situ and in real time with both atomic scaled resolution and collective information. The results are helpful in revealing the mechanism of structural-specified synthesis of single-walled carbon nanotubes. This research offers an example of systematic investigation at the atomic scale on catalysts under reactive conditions. Such catalysts presenting high structural stability may also find applications in other structure-specific synthesis.