Atomic origin of CO-Interaction effect of PtPb@Pt catalyst revealed by in situ environmental transmission electron microscopy. (October 2020)

• Record Type: Journal Article
• Authors: Wang, Qi; Xia, Guang-Jie; Zhao, Zhi Liang; Zhu, Yuanmin; Shi, Xiaobo; Huang, Limin; Wang, Yang-Gang; Gu, Meng
• Is Part Of: Nano energy. Volume 76(2020)
• Publication Date: 2020-10
• Subjects: CO-interaction -- PtPb@Pt catalyst -- In-situ TEM -- AIMD -- DFT calculation; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanostructured materials -- Periodicals; Power resources -- Technological innovations -- Periodicals; Nanoscience; Nanostructured materials; Nanotechnology; Power resources -- Technological innovations; Periodicals; 621.042
• DOI: 10.1016/j.nanoen.2020.105099
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: The carbon monoxide (CO) interaction effect on active Pt-based catalysts is critical because the surface reconstruction and phase separation behavior of bimetallic catalysts in a CO environment can profoundly impact the catalysts' activity and durability. However, because direct and dynamic observation has proven elusive, the exact failure mechanisms of the nanocrystal structural modifications induced by CO are poorly understood. In this work, we probe the dynamic structural and compositional transformations of an individual PtPb@Pt nanoplates in a CO gas atmosphere via in-situ environmental transmission electron microscopy (ETEM) and confirmed with theoretical calculations. The interaction of Pt and Pb atoms with CO molecules are revealed dynamically, including the resulting breakdown of the PtPb@Pt nanoplates. The Pt atoms aggregate on surface facets of the original PtPb lattice and the Pt-CO complex mobilizes, cracking the Pt surface layers and stripping Pb atoms from the PtPb alloy core to form Pb(CO)4 . These interactions provide direct clues for the failure analysis of the catalyst and, thus, represent a critical step towards the design of an anti-CO interaction catalyst. Graphical abstract: Image 1 Highlights: The atomically response of Pt and PtPb alloy to CO molecule was witnessed. The reconstruction of an individual PtPb@Pt nanoplate was tracked, indicating the failure mechanism of catalyst. The intermediate of Pb-CO was directedly observed during the evolution process. AIMD and DFT calculations illuminated the strong metal-gas interactions consequently lead to structural breakdown.