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Atomic origin of CO-Interaction effect of PtPb@Pt catalyst revealed by in situ environmental transmission electron microscopy
Nano Energy ( IF 16.8 ) Pub Date : 2020-07-02 , DOI: 10.1016/j.nanoen.2020.105099
Qi Wang , Guang-Jie Xia , Zhi Liang Zhao , Yuanmin Zhu , Xiaobo Shi , Limin Huang , Yang-Gang Wang , Meng Gu

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.



中文翻译:

原位环境透射电镜揭示PtPb @ Pt催化剂CO相互作用的原子起源

一氧化碳(CO)对活性基于Pt的催化剂的相互作用至关重要,因为在CO环境中双金属催化剂的表面重建和相分离行为会深刻影响催化剂的活性和耐久性。但是,由于直接和动态观察已被证明难以捉摸,因此对由CO引起的纳米晶体结构修饰的确切破坏机理了解甚少。在这项工作中,我们通过原位探测在CO气体气氛中单个PtPb @ Pt纳米板的动态结构和组成转变环境透射电子显微镜(ETEM)并通过理论计算得到证实。动态揭示了Pt和Pb原子与CO分子的相互作用,包括PtPb @ Pt纳米板的分解结果。Pt原子聚集在原始PtPb晶格的表面上,并且Pt-CO络合物动员,使Pt表面层破裂,并从PtPb合金核中剥离Pb原子,形成Pb(CO)4。这些相互作用为催化剂的失效分析提供了直接线索,因此代表了抗CO相互作用催化剂设计的关键步骤。

更新日期:2020-07-02
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