CO Oxidation on Technological Pd-Al2O3 Catalysts: Oxidation State and Activity
Artikel i vetenskaplig tidskrift, 2011

The specific CO oxidation activity of palladium versus palladium oxide is still controversially discussed. In this study, 5 wt. % Pd-gamma-Al2O3 catalysts were utilized to investigate the effect of the palladium oxidation state on the CO oxidation activity. Comprehensive in situ and ex situ characterization of different alumina supported PdOx (x = 0-1) phases (by HR-TEM, XRD, and FTIR spectroscopy), combined with kinetic measurements and DFT calculations of CO adsorption, allowed us to assess the catalytic activity of the different PdOx (x = 0-1) species: Supported Pd-0 and substoichiometric PdOx<1 exhibited comparable high activities, due to a rapid reduction of PdOx<1 to Pd upon CO exposure. PdO nanoparticles showed a lower catalytic activity resulting from their higher stability against reduction by CO. The limited extent of oxidation of Pd under typical reaction conditions together with the facile reduction of substoichiometric PdOx<1 suggest that the active phase present under the current reaction conditions is oxygen-covered metallic Pd.

functional theory calculations

single-crystal surfaces

pd nanoparticles

ultrahigh-vacuum

metals

sum-frequency generation

supported palladium catalysts

pt-group

reflection-absorption spectroscopy

scanning-tunneling-microscopy

model catalysts

Författare

K. Zorn

Technische Universität Wien

S. Giorgio

CNRS Centre National de la Recherche Scientifique

E. Halwax

Technische Universität Wien

C. R. Henry

CNRS Centre National de la Recherche Scientifique

Henrik Grönbeck

Kompetenscentrum katalys (KCK)

Chalmers, Teknisk fysik, Kemisk fysik

G. Rupprechter

Technische Universität Wien

Journal of Physical Chemistry C

1932-7447 (ISSN) 1932-7455 (eISSN)

Vol. 115 1103-1111

Styrkeområden

Nanovetenskap och nanoteknik

Energi

Materialvetenskap

Fundament

Grundläggande vetenskaper

Ämneskategorier

Atom- och molekylfysik och optik

Kemi

DOI

10.1021/jp106235x