Tuning Pt-CeO2 interactions by high-temperature vapor-phase synthesis for improved reducibility of lattice oxygen

Xavier Isidro Pereira-Hernández; Andrew DeLaRiva; Valery Muravev; Deepak Kunwar; Haifeng Xiong; Berlin Sudduth; Mark Engelhard; Libor Kovarik; Emiel J M Hensen; Yong Wang; Abhaya K Datye

doi:10.1038/s41467-019-09308-5

Tuning Pt-CeO₂ interactions by high-temperature vapor-phase synthesis for improved reducibility of lattice oxygen

Nat Commun. 2019 Mar 25;10(1):1358. doi: 10.1038/s41467-019-09308-5.

Authors

Affiliations

¹ Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, Washington, 99164, USA.
² Department of Chemical and Biological Engineering and Center for Micro-Engineered Materials, University of New Mexico, Albuquerque, New Mexico, 87131, USA.
³ Laboratory of Inorganic Materials and Catalysis, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven, The Netherlands.
⁴ Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington, 99354, USA.
⁵ Laboratory of Inorganic Materials and Catalysis, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven, The Netherlands. e.j.m.hensen@tue.nl.
⁶ Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, Washington, 99164, USA. yong.wang@pnnl.gov.
⁷ Institute for Integrated Catalysis, Pacific Northwest National Laboratory, Richland, Washington, 99354, USA. yong.wang@pnnl.gov.
⁸ Department of Chemical and Biological Engineering and Center for Micro-Engineered Materials, University of New Mexico, Albuquerque, New Mexico, 87131, USA. datye@unm.edu.

Abstract

In this work, we compare the CO oxidation performance of Pt single atom catalysts (SACs) prepared via two methods: (1) conventional wet chemical synthesis (strong electrostatic adsorption-SEA) with calcination at 350 °C in air; and (2) high temperature vapor phase synthesis (atom trapping-AT) with calcination in air at 800 °C leading to ionic Pt being trapped on the CeO₂ in a thermally stable form. As-synthesized, both SACs are inactive for low temperature (<150 °C) CO oxidation. After treatment in CO at 275 °C, both catalysts show enhanced reactivity. Despite similar Pt metal particle size, the AT catalyst is significantly more active, with onset of CO oxidation near room temperature. A combination of near-ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) and CO temperature-programmed reduction (CO-TPR) shows that the high reactivity at low temperatures can be related to the improved reducibility of lattice oxygen on the CeO₂ support.

Publication types

Research Support, U.S. Gov't, Non-P.H.S.
Research Support, Non-U.S. Gov't