TY - JOUR
T1 - Atomic-Scale Determination of Active Facets on the MoVTeNb Oxide M1 Phase and Their Intrinsic Catalytic Activity for Ethane Oxidative Dehydrogenation
AU - Melzer, Daniel
AU - Xu, Pinghong
AU - Hartmann, Daniela
AU - Zhu, Yuanyuan
AU - Browning, Nigel D.
AU - Sanchez-Sanchez, Maricruz
AU - Lercher, Johannes A.
N1 - Publisher Copyright:
© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
PY - 2016/7/25
Y1 - 2016/7/25
N2 - Aberration-corrected high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) has been used to image the basal {001} plane of the catalytically relevant M1 phase in MoVTeNb complex oxides. Facets {010}, {120}, and {210} are identified as the most frequent lateral termination planes of the crystals. Combination of STEM with He ion microscopy (HIM) images, Rietveld analysis, and kinetic tests reveals that the activation of ethane is correlated to the availability of facets {001}, {120}, and {210} at the surface of M1 crystals. The lateral facets {120} and {210} expose crystalline positions related to the typical active centers described for propane oxidation. Conversely, the low activity of the facet {010} is attributed to its configuration, consisting of only stable M6O21units connected by a single octahedron. Thus, we quantitatively demonstrated that differences in catalytic activity among M1 samples of equal chemical composition depend primarily on the morphology of the particles, which determines the predominant terminating facets.
AB - Aberration-corrected high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) has been used to image the basal {001} plane of the catalytically relevant M1 phase in MoVTeNb complex oxides. Facets {010}, {120}, and {210} are identified as the most frequent lateral termination planes of the crystals. Combination of STEM with He ion microscopy (HIM) images, Rietveld analysis, and kinetic tests reveals that the activation of ethane is correlated to the availability of facets {001}, {120}, and {210} at the surface of M1 crystals. The lateral facets {120} and {210} expose crystalline positions related to the typical active centers described for propane oxidation. Conversely, the low activity of the facet {010} is attributed to its configuration, consisting of only stable M6O21units connected by a single octahedron. Thus, we quantitatively demonstrated that differences in catalytic activity among M1 samples of equal chemical composition depend primarily on the morphology of the particles, which determines the predominant terminating facets.
KW - heterogeneous catalysis
KW - oxidative dehydrogenation
KW - scanning probe microscopy
KW - surface chemistry
KW - surface structures
UR - http://www.scopus.com/inward/record.url?scp=84961285299&partnerID=8YFLogxK
U2 - 10.1002/anie.201600463
DO - 10.1002/anie.201600463
M3 - Article
C2 - 26990594
AN - SCOPUS:84961285299
SN - 1433-7851
VL - 55
SP - 8873
EP - 8877
JO - Angewandte Chemie International Edition in English
JF - Angewandte Chemie International Edition in English
IS - 31
ER -