Local Structure and Electronic State of Atomically Dispersed Pt Supported on Nanosized CeO2

作者：Matthew A. Kottwitz, Yuanyuan Li, Robert M. Palomino, Zongyuan Liu, Guangjin Wang, Qin Wu, Jiahao Huang, Janis Timoshenko, Sanjaya D. Senanayake, Mahalingam Balasubramanian, Deyu Lu, Ralph G. Nuzzo, Anatoly I. Frenkel · 发表于：ACS Catalysis · 年份：2019 · DOI：10.1021/acscatal.9b02083 · 被引用次数：127 · 研究领域：Catalytic Processes in Materials Science、Catalysis and Oxidation Reactions、Electrocatalysts for Energy Conversion

Single atom catalysts (SACs) have shown high activity and selectivity in a growing number of chemical reactions. Many efforts aimed at unveiling the structure–property relationships underpinning these activities and developing synthesis methods for obtaining SACs with the desired structures are hindered by the paucity of experimental methods capable of probing the attributes of local structure, electronic properties, and interaction with support—features that comprise key descriptors of their activity. In this work, we describe a combination of experimental and theoretical approaches that include photon and electron spectroscopy, scattering, and imaging methods, linked by density functional theory calculations, for providing detailed and comprehensive information on the atomic structure and electronic properties of SACs. This characterization toolbox is demonstrated here using a model single atom Pt/CeO 2 catalyst prepared via a sol–gel-based synthesis method. Isolated Pt atoms together with extra oxygen atoms passivate the (100) surface of nanosized ceria. A detailed picture of the local structure of Pt nearest environment emerges from this work involving the bonding of isolated Pt 2+ ions at the hollow sites of perturbed (100) surface planes of the CeO 2 support, as well as a substantial (and heretofore unrecognized) strain within the CeO 2 lattice in the immediate vicinity of the Pt centers. The detailed information on structural attributes provided by our approach is the ...