TY - JOUR
T1 - Tuning Strong Metal-Support Interaction Kinetics on Pt-Loaded TiO2(110) by Choosing the Pressure
T2 - A Combined Ultrahigh Vacuum/Near-Ambient Pressure XPS Study
AU - Petzoldt, Philip
AU - Eder, Moritz
AU - Mackewicz, Sonia
AU - Blum, Monika
AU - Kratky, Tim
AU - Günther, Sebastian
AU - Tschurl, Martin
AU - Heiz, Ueli
AU - Lechner, Barbara A.J.
N1 - Publisher Copyright:
© 2022 American Chemical Society. All rights reserved.
PY - 2022/9/29
Y1 - 2022/9/29
N2 - Pt catalyst particles on reducible oxide supports often change their activity significantly at elevated temperatures due to the strong metal-support interaction (SMSI), which induces the formation of an encapsulation layer around the noble metal particles. However, the impact of oxidizing and reducing treatments at elevated pressures on this encapsulation layer remains controversial, partly due to the "pressure gap" between surface science studies and applied catalysis. In the present work, we employ synchrotron-based near-ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) to study the effect of O2and H2on the SMSI-state of well-defined Pt/TiO2(110) catalysts at pressures of up to 0.1 Torr. By tuning the O2pressure, we can either selectively oxidize the TiO2support or both the support and the Pt particles. Catalyzed by metallic Pt, the encapsulating oxide overlayer grows rapidly in 1 × 10-5Torr O2, but orders of magnitude less effectively at higher O2pressures, where Pt is in an oxidic state. While the oxidation/reduction of Pt particles is reversible, they remain embedded in the support once encapsulation has occurred.
AB - Pt catalyst particles on reducible oxide supports often change their activity significantly at elevated temperatures due to the strong metal-support interaction (SMSI), which induces the formation of an encapsulation layer around the noble metal particles. However, the impact of oxidizing and reducing treatments at elevated pressures on this encapsulation layer remains controversial, partly due to the "pressure gap" between surface science studies and applied catalysis. In the present work, we employ synchrotron-based near-ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) to study the effect of O2and H2on the SMSI-state of well-defined Pt/TiO2(110) catalysts at pressures of up to 0.1 Torr. By tuning the O2pressure, we can either selectively oxidize the TiO2support or both the support and the Pt particles. Catalyzed by metallic Pt, the encapsulating oxide overlayer grows rapidly in 1 × 10-5Torr O2, but orders of magnitude less effectively at higher O2pressures, where Pt is in an oxidic state. While the oxidation/reduction of Pt particles is reversible, they remain embedded in the support once encapsulation has occurred.
UR - http://www.scopus.com/inward/record.url?scp=85138949689&partnerID=8YFLogxK
U2 - 10.1021/acs.jpcc.2c03851
DO - 10.1021/acs.jpcc.2c03851
M3 - Article
AN - SCOPUS:85138949689
SN - 1932-7447
VL - 126
SP - 16127
EP - 16139
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
IS - 38
ER -