Understanding the Intrinsic Surface Reactivity of Single-Layer and Multilayer PdO(101) on Pd(100)

DSpace Repository

Understanding the Intrinsic Surface Reactivity of Single-Layer and Multilayer PdO(101) on Pd(100)

Details

Files for download

Find Full text There are no files associated with this item..

Overview of item record
Publication Article, peer reviewed scientific
Title Understanding the Intrinsic Surface Reactivity of Single-Layer and Multilayer PdO(101) on Pd(100)
Author Mehar, Vikram ; Kim, Minkyu ; Shipilin, Mikhail ; Van den Bossche, Maxime ; Gustafson, Johan ; Merte, Lindsay Richard ; Hejral, Uta ; Gronbeck, Henrik ; Lundgren, Edvin ; Asthagiri, Aravind ; Weaver, Jason F.
Date 2018
English abstract
We investigated the intrinsic reactivity of CO on single-layer and multilayer PdO(101) grown on Pd(100) using temperature-programmed reaction spectroscopy (TPRS) and reflection absorption infrared spectroscopy (RAIRS) experiments, as well as density functional theory (DFT) calculations. We find that CO binds more strongly on multilayer than single-layer PdO(101) (similar to 119 kJ/mol vs 43 kJ/mol), and that CO oxidizes negligibly on single-layer PdO(101), whereas nearly 90% of a saturated layer of CO oxidizes on multilayer PdO(101) during TPRS experiments. RAIRS further shows that CO molecules adsorb on both bridge-Pd-cus and atop-Pd-cus sites (coordinatively unsaturated Pd sites) of single-layer PdO(101)/Pd(100), while CO binds exclusively on atop-Pd-cus sites of multilayer PdO(101). The DFT calculations reproduce the much stronger binding of CO on multilayer PdO(101), as well as the observed binding site preferences, and reveal that the stronger binding is entirely responsible for the higher CO oxidation activity of multilayer PdO(101)/Pd(100). We show that the O atom below the Pd-cus site, present only on multilayer PdO(101), modifies the electronic states of the Pd-cus, atom in a way that enhances the CO-Pd-cus bonding. Lastly, we show that a precursor -mediated kinetic model, with energetics determined from the present study, predicts that the intrinsic CO oxidation rates achieved on both single-layer and multilayer PdO(101)/Pd(100) can be expected to exceed the gaseous CO diffusion rate to the surface during steady-state CO oxidation at elevated pressures, even though the intrinsic reaction rates are 4-5 orders of magnitude lower on single-layer PdO(101)/Pd(100) than on multilayer PdO(101)/Pd(100).
DOI https://doi.org/10.1021/acscatal.8b02191 (link to publisher's fulltext.)
Publisher American Chemical Society
Host/Issue ACS Catalysis;9
Volume 8
ISSN 2155-5435
Language eng (iso)
Subject CO oxidation
Pd(100)
PdO
palladium
infrared spectroscopy
RAIRS
DFT
surface oxide
Sciences
Research Subject Categories::NATURAL SCIENCES
Handle http://hdl.handle.net/2043/26698 Permalink to this page
Facebook

This item appears in the following Collection(s)

Details

Search


Browse

My Account

Statistics