Affiliations: Labs. Química-Física and Catálisis Computacional, Fisicoquímica de Superficies, Centro de Química, IVIC, Caracas, Venezuela
Correspondence:
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Corresponding author: Beulah Griffe, Labs. Química-Física and Catálisis Computacional, Fisicoquímica de Superficies, Centro de Química, IVIC, Caracas 1020-A, Venezuela. E-mail:[email protected]
Abstract: Quantum chemistry calculations were carried out using the ONIOM2 methodology
at two different levels of calculation, B3LYP for the high level and UFF for
the low level. These calculations were performed on aggregates to analyze
the geometries of small clusters of Au1-3 and Cu1-3 supported
on SAPO-11. Similarly CO-Au1-3/SAPO-11 and CO-Cu1-3/SAPO-11 moieties obtained by their interaction with CO, were calculated and the
results of both cases are compared. The formation energy ΔEF of
the metal aggregates and with CO adsorption, C-O and M-CO bond distances and
calculated C=O stretching frequencies are reported.The most stable
structures of the aggregates of Au1-3 and Cu1-3/SAPO-11 are
similar, Au3 exhibits
acute triangle
geometry and Cu3 shows
isosceles triangle with a large side
geometry. The CO ΔEads values reveal that the CO
adsorption is more stable in Au1-3/SAPO-11 than in Cu1-3/SAPO-11. Au-CO distances are larger than Cu-CO.
