Origin and Tunability of Unusually Large Surface Capacitance in Doped Cerium Oxide Studied by Ambient-Pressure X-Ray Photoelectron Spectroscopy

Chirranjeevi Balaji Gopal; Farid El Gabaly; Anthony H McDaniel; William C Chueh

doi:10.1002/adma.201506333

Origin and Tunability of Unusually Large Surface Capacitance in Doped Cerium Oxide Studied by Ambient-Pressure X-Ray Photoelectron Spectroscopy

Adv Mater. 2016 Jun;28(23):4692-7. doi: 10.1002/adma.201506333. Epub 2016 Mar 31.

Authors

Chirranjeevi Balaji Gopal¹, Farid El Gabaly², Anthony H McDaniel², William C Chueh^{1

2

3}

Affiliations

¹ Department of Materials Science and Engineering, Stanford University, 496 Lomita Mall, Stanford, CA, 94305, USA.
² Sandia National Laboratories, Livermore, CA, 94550, USA.
³ Stanford Institute of Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA.

PMID: 27031580
DOI: 10.1002/adma.201506333

Abstract

The volumetric redox (chemical) capacitance of the surface of CeO2-δ films is quantified in situ to be 100-fold larger than the bulk values under catalytically relevant conditions. Sm addition slightly lowers the surface oxygen nonstoichiometry, but effects a 10-fold enhancement in surface chemical capacitance by mitigating defect interactions, highlighting the importance of differential nonstoichiometry for catalysis.

Keywords: catalysis; ceria; interfacial; nonstoichiometry; redox.