LaFeO₃ films on SiO₂ for supported-Pt catalysts

ABSTRACT

LaFeO₃ films were deposited to a thickness of 0.5 nm onto amorphous SiO₂ by Atomic Layer Deposition and used as supports for Pt. Uniform coverage of the SiO₂ was demonstrated by Scanning Transmission Electron Microscopy (STEM) and Temperature Programmed Desorption (TPD) of 2-propanol. The films were found to be amorphous to X-Ray Diffraction, but the reducibility of the Fe in the films and the ability of the films to maintain high Pt dispersions following harsh redox treatments suggested that the perovskite phase was formed on a short length scale. Similar to results found on Pt/LaFeO₃/MgAl₂O₄, Pt/LaFeO₃/SiO₂ catalysts maintained a high Pt dispersion following redox cycling at 1073 K and showed high activity for CO oxidation following high-temperature reduction. The implications for using these materials is discussed.

KEYWORDS:

• CO oxidation
• Pt catalyst
• Atomic layer deposition
• Thin film

Acknowledgments

This work was supported by the Air Force Office of Scientific Research, under AFOSR Award No. FA9550-19-1-0326. This work was carried out in part at the Singh Center for Nanotechnology, part of the National Nanotechnology Coordinated Infrastructure Program, which is supported by the National Science Foundation grant NNCI-1542153. The authors would like to express their gratitude to Dr. Xinyu Mao and Dr. Chao Lin for their fruitful discussion and the high-resolution STEM images in the supplementary material.

Additional information

Funding

This work was carried out in part at theSinghCenter for Nanotechnology, part of the National Nanotechnology Coordinated Infrastructure Program, which is supported by the National Science Foundation grant NNCI-2025608.