TY - JOUR
T1 - Role of the nanoscale in catalytic CO oxidation by supported Au and Pt nanostructures
AU - Rashkeev, Sergey N.
AU - Lupini, Andrew R.
AU - Overbury, Steven H.
AU - Pennycook, Stephen J.
AU - Pantelides, Sokrates T.
PY - 2007/7/30
Y1 - 2007/7/30
N2 - Experiments have found that the catalytic activity of Au increases sharply for supported nanoparticles smaller than 5 nm, while Pt exhibits the opposite behavior. Several authors, seeking to explain the nanoscale Au activity, reached conflicting conclusions, attributing it to different nanoscale features or to a particular bilayer structure that is independent of size. Here, we report an extensive theoretical study of a large ensemble of Ti O2 -supported Au and Pt nanoparticles and show that several nanoscale features collectively result in the observed contrasting behavior. Low coordination is accompanied by bond weakening in Au and strengthening in Pt, while perimeter sites are active only for Au. Though there are orbital-occupancy differences for catalytically active and inactive configurations, there is insignificant variation in physical-charge transfer. Finally, we report atomically resolved Z -contrast images that confirm bond weakening in catalytically active Ti O2 -supported Au nanoparticles.
AB - Experiments have found that the catalytic activity of Au increases sharply for supported nanoparticles smaller than 5 nm, while Pt exhibits the opposite behavior. Several authors, seeking to explain the nanoscale Au activity, reached conflicting conclusions, attributing it to different nanoscale features or to a particular bilayer structure that is independent of size. Here, we report an extensive theoretical study of a large ensemble of Ti O2 -supported Au and Pt nanoparticles and show that several nanoscale features collectively result in the observed contrasting behavior. Low coordination is accompanied by bond weakening in Au and strengthening in Pt, while perimeter sites are active only for Au. Though there are orbital-occupancy differences for catalytically active and inactive configurations, there is insignificant variation in physical-charge transfer. Finally, we report atomically resolved Z -contrast images that confirm bond weakening in catalytically active Ti O2 -supported Au nanoparticles.
UR - http://www.scopus.com/inward/record.url?scp=34547518873&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.76.035438
DO - 10.1103/PhysRevB.76.035438
M3 - Article
AN - SCOPUS:34547518873
SN - 1098-0121
VL - 76
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
IS - 3
M1 - 035438
ER -