Stabilization of Au(III) on heterogeneous catalysts and their catalytic similarities with homogeneous Au(III) metal organic complexes

We have found that nanocrystalline CeO2 and Y2O3 are able to stabilize surface Au(III) species, with the final catalyst presenting a direct correlation between the concentration of these species and the catalytic activity for CO oxidation. The same catalysts are also active and extremely selective in performing the homocoupling of arylboronic acids, being the activity directly correlated with Au(III). By preparing Schiff base, Au(Iota Iota Iota) complexes we have confirmed that Au(III) is very active and selective for the homocoupling reaction, while the analogous Pd(Iota Iota) metal complex catalyzes the Suzuki cross-coupling reaction. These Au(Iota Iota Iota) complexes are also very active catalysts, for olefin hydrogenation, giving similar activities than the "isoelectronic" Pd(II) metal complex. (c) 2005 Elsevier B.V. All rights reserved.