Isotopic oxygen exchange on supported Ru and Au catalysts

Abstract

The isotopic exchange reaction of molecular oxygen is applied to supported ruthenium and gold catalysts. The results on supported ruthenium are similar to those on RuO2. The exchange reaction seems to be unaffected by differences in particle size or nature of the support (MgO or SiO2, respectively). The heterogeneous exchange kinetics deviate from an exponential law. This indicates the presence of nonuniformities on the catalyst surface and/or a contribution of oxygen diffusion. On supported gold, high exchange activity and massive uptake of labeled oxygen by the solid phase are observed. Au/MgO is one order of magnitude more active than Au/SiO2. The activation of support oxygen for the isotopic exchange reaction is related to an interaction between gold and support.