Dynamical Observation and Detailed Description of Catalysts under Strong Metal–Support Interaction

Shuyi Zhang, Philipp N Plessow, Joshua J. Willis, Sheng Dai, Mingjie Xu, George W. Graham, Matteo Cargnello, Frank Abild-Pedersen, Xiaoqing Pan
Year of publication: 
Nano Letters

Understanding the structures of catalysts under realistic conditions with atomic precision is crucial to design

better materials for challenging transformations. Under reducing conditions, certain reducible supports migrate onto supported

metallic particles and create strong metal−support states that drastically change the reactivity of the systems. The details of this

process are still unclear and preclude its thorough exploitation. Here, we report an atomic description of a palladium/titania (Pd/

TiO2) system by combining state-of-the-art in situ transmission electron microscopy and density functional theory (DFT)

calculations with structurally defined materials, in which we visualize the formation of the overlayers at the atomic scale under

atmospheric pressure and high temperature. We show that an amorphous reduced titania layer is formed at low temperatures,

and that crystallization of the layer into either mono- or bilayer structures is dictated by the reaction environment and predicted

by theory. Furthermore, it occurs in combination with a dramatic reshaping of the metallic surface facets.

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