Journal
SCIENCE CHINA-MATERIALS
Volume 64, Issue 5, Pages 1256-1266Publisher
SCIENCE PRESS
DOI: 10.1007/s40843-020-1529-3
Keywords
surface segregation; clustering; Cu(Au) alloy; environmental TEM; CO
Categories
Funding
- National Natural Science Foundation of China [21873069, 11504162]
- Collaborative Innovation Center of Sustainable Energy Materials in Guangxi University
Ask authors/readers for more resources
The compositional and phase segregation on the surface of an alloy can alter its functionality, especially in applications where surface structure and chemistry are crucial. The atomic processes during gas molecule-induced segregation remain elusive.
Surface compositional and phase segregation in an alloy can change its functionality, especially for applications where surface structure and chemistry play a vital role. For instance, the surface status of alloy catalysts significantly affects their catalytic performance for both heterogeneous and electrochemical processes. Surface segregation is believed to be driven by the difference in surface energy to reduce the total free energy of the alloy. However, the atomistic processes during the segregation process remain elusive, especially for gas molecule-induced segregation, where both structural and chemical reordering may occur. Herein, we achieved in-situ atomic-scale visualization of the surface segregation behaviors of a solid solution Cu(Au) alloy under the CO gas by an aberration-corrected environmental transmission electron microscope. CO-induced Cu(Au) surface ordering structures largely change the surface chemistry of the alloy. Further gas exposure at elevated temperature could facilitate Au atom diffusion through a specific atomic channel structure for dealloying and clustering on the surface. The segregated Au nanoparticles show rich phase and morphological dynamics interacting with the alloy surface, where the gas adsorption also plays an important role. These atomic insights provide direct evidence for the surface segregation and dealloying mechanisms of bimetallic alloys, and highlight the role of gas adsorbate in these surface processes.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available