Sintering Activated Atomic Palladium Catalysts with High-Temperature Tolerance of ∼1,000°C

Yang, N. and Zhao, Y. and Zhang, H. and Xiang, W. and Sun, Y. and Yang, S. and Sun, Y. and Zeng, G. and Kato, K. and Li, X. and Yamauchi, M. and Jiang, Z. and Li, T.

Volume: 2 Pages:
DOI: 10.1016/j.xcrp.2020.100287
Published: 2021

Sintering-induced aggregation of active metals is a major cause of catalyst deactivation. Catalysts that can operate above 800°C are rare. Here, we report an unusual noble metal catalyst with sintering-induced activation at temperatures up to 1,000°C. The catalyst consists of atomically dispersed palladium embedded in a reducible SnO2 support designated for lean methane combustion. High temperature reaction simultaneously causes favorable changes of palladium ensemble state combining synergistically with lattice oxygen activation. Such changes lead to at least one order of magnitude improvement of the intrinsic reactivity, which compensates the surface area loss. Extensive characterizations such as atom probe tomography, X-ray absorption spectroscopy, and isotope tracking together with theoretical calculations illustrate the structure and surface chemistry changes and their impacts on the reaction mechanism. The catalyst also shows notable long-term stability and facile regeneration after poisoning. Our work may provide new insights into designing active and thermally stable catalysts. © 2020 The Author(s) Yang et al. report that atomic Pd catalysts on SnO2 undergo sintering of both Pd and support during high-temperature catalytic oxidation process. The sintered catalyst not only shows significant increase in activity for methane combustion under harsh reaction conditions, but also retains catalytic stability with high-temperature tolerance up to 1,000°C. © 2020 The Author(s)

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