TY - JOUR
T1 - Thermal Oxidation of Size-Selected Pd Nanoparticles Supported on CuO Nanowires
T2 - The Role of the CuO-Pd Interface
AU - Steinhauer, Stephan
AU - Zhao, Junlei
AU - Singh, Vidyadhar
AU - Pavloudis, Theodore
AU - Kioseoglou, Joseph
AU - Nordlund, Kai
AU - Djurabekova, Flyura
AU - Grammatikopoulos, Panagiotis
AU - Sowwan, Mukhles
N1 - Publisher Copyright:
© 2017 American Chemical Society.
PY - 2017/7/25
Y1 - 2017/7/25
N2 - The structure of heterogeneous nanocatalysts supported on metal oxide materials and their morphological changes during oxidation/reduction processes play a crucial role in determining the resulting catalytic activity. Herein, we study the thermal oxidation mechanism of Pd nanoparticles supported on CuO nanowires by combining in situ environmental transmission electron microscopy (TEM), ex situ experiments, and ab initio density functional theory (DFT) calculations. High-resolution TEM imaging assisted by geometric phase analysis enabled the analysis of partially oxidized, fully oxidized, and distinct onion-like Pd nanoparticles with subsurface dislocations. Furthermore, preferential crystalline orientations between PdO nanoparticles and the CuO nanowire support have been found. Hence, the CuO-Pd interface is crucial for the thermal oxidation of Pd nanoparticles, as corroborated by electron energy loss spectroscopy and DFT calculations. The latter revealed a considerably lower energy barrier for penetration of oxygen into the Pd lattice at the CuO-Pd interface, promoting nanoparticle oxidation. The obtained results are compared with those of literature reports on different material systems, and potential implications for catalysis and chemoresistive sensing applications are discussed.
AB - The structure of heterogeneous nanocatalysts supported on metal oxide materials and their morphological changes during oxidation/reduction processes play a crucial role in determining the resulting catalytic activity. Herein, we study the thermal oxidation mechanism of Pd nanoparticles supported on CuO nanowires by combining in situ environmental transmission electron microscopy (TEM), ex situ experiments, and ab initio density functional theory (DFT) calculations. High-resolution TEM imaging assisted by geometric phase analysis enabled the analysis of partially oxidized, fully oxidized, and distinct onion-like Pd nanoparticles with subsurface dislocations. Furthermore, preferential crystalline orientations between PdO nanoparticles and the CuO nanowire support have been found. Hence, the CuO-Pd interface is crucial for the thermal oxidation of Pd nanoparticles, as corroborated by electron energy loss spectroscopy and DFT calculations. The latter revealed a considerably lower energy barrier for penetration of oxygen into the Pd lattice at the CuO-Pd interface, promoting nanoparticle oxidation. The obtained results are compared with those of literature reports on different material systems, and potential implications for catalysis and chemoresistive sensing applications are discussed.
UR - http://www.scopus.com/inward/record.url?scp=85026296661&partnerID=8YFLogxK
U2 - 10.1021/acs.chemmater.7b02242
DO - 10.1021/acs.chemmater.7b02242
M3 - 文章
AN - SCOPUS:85026296661
SN - 0897-4756
VL - 29
SP - 6153
EP - 6160
JO - Chemistry of Materials
JF - Chemistry of Materials
IS - 14
ER -