TY  - JOUR
AU  - Müller, Patrick
AU  - Hejral, Uta
AU  - Rütt, Uta
AU  - Stierle, Andreas
TI  - In situ Oxidation study of Pd-Rh Nanoparticles on MgAl<sub>2</sub>O<sub>4</sub>(001)
JO  - Physical chemistry, chemical physics
VL  - 16
IS  - 27
SN  - 1463-9084
CY  - Cambridge
PB  - RSC Publ.
M1  - PUBDB-2015-00997
SP  - 13866 - 13874
PY  - 2014
N1  - (c) the Owner Societies. Post referee full text in progress. Embargo full text 1 year from 19 May 2014.
AB  - Alloy nanoparticles on oxide supports are widely used as heterogeneous catalysts in reactions involving oxygen. Here we discuss the oxidation behavior of Pd–Rh alloy nanoparticles on MgAl2O4(001) supports with a particle diameter from 6–11 nm. As an In situ tool, we employed high energy grazing incidence X-ray diffraction at a photon energy of 85 keV. We find that physical vapor deposited Pd–Rh nanoparticles grow epitaxially on MgAl2O4(001) with a truncated octahedral shape over the whole concentration range. During our systematic oxidation experiments performed at 670 K in the pressure range from 10^−3 to 0.1 mbar, we observe for Rh containing nanoparticles the formation of two different Rh oxide phases, namely RhO2 and a spinel-like Rh3O4 phase. PdO formation is only observed for pure Pd nanoparticles. This oxidation induced segregation behavior is also reflected in the oxidation induced enlargement of the average nanoparticle lattice parameter towards to value for pure Pd. Our results have ramifications for the phase separation behavior of alloy nanocatalysts under varying reducing and oxidizing environments.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000338116700038
C6  - pmid:24894349
DO  - DOI:10.1039/c4cp01271b
UR  - https://bib-pubdb1.desy.de/record/206533
ER  -