Carbon-supported palladium catalysts. Molecular orbital study

TY - JOUR

T1 - Carbon-supported palladium catalysts. Molecular orbital study

AU - Efremenko, Irena

AU - Sheintuch, Moshe

N1 - Funding Information: This research was supported by the Ministry of Science. I.E. is partially supported by the Center for Absorption in Science, State of Israel. M.S. is a member of the Institute of Catalysis of the Technion.

PY - 2003/2/15

Y1 - 2003/2/15

N2 - Geometric and electronic structures of palladium clusters supported on activated carbon (Pdn/AC) are analyzed using semiempirical quantum chemical modeling for n=1-22. Qualitative reliability of the results is checked by DFT calculations for n=1-6. Supported Pd atoms and clusters are shown to be strongly bound to unsaturated and defect surface sites. In such positions, interaction of Pd atoms with the support is much stronger than that with each other. That provides the driving force for atomic dispersity of Pd/AC catalysts. Geometry of small clusters is determined by morphology of an adhesion position. Nanosized particles form compact three-dimensional structures with close-packed triangular surfaces. AC support causes notable excitations in the electronic structure of metal atoms directly bound to the support, resulting in the direct nucleation of fcc-like structures. These excitations are quickly extinguishing when moving far from the support surface.

AB - Geometric and electronic structures of palladium clusters supported on activated carbon (Pdn/AC) are analyzed using semiempirical quantum chemical modeling for n=1-22. Qualitative reliability of the results is checked by DFT calculations for n=1-6. Supported Pd atoms and clusters are shown to be strongly bound to unsaturated and defect surface sites. In such positions, interaction of Pd atoms with the support is much stronger than that with each other. That provides the driving force for atomic dispersity of Pd/AC catalysts. Geometry of small clusters is determined by morphology of an adhesion position. Nanosized particles form compact three-dimensional structures with close-packed triangular surfaces. AC support causes notable excitations in the electronic structure of metal atoms directly bound to the support, resulting in the direct nucleation of fcc-like structures. These excitations are quickly extinguishing when moving far from the support surface.

KW - Activated carbon

KW - Clusters

KW - DFT

KW - Palladium

KW - Semiempirical quantum chemical modeling

KW - Supported catalysts

UR - http://www.scopus.com/inward/record.url?scp=0141565632&partnerID=8YFLogxK

U2 - 10.1016/S0021-9517(02)00103-3

DO - 10.1016/S0021-9517(02)00103-3

M3 - 文章

AN - SCOPUS:0141565632

SN - 0021-9517

VL - 214

SP - 53

EP - 67

JO - Journal of Catalysis

JF - Journal of Catalysis

IS - 1

ER -