Thermally Activated Formation of Reactive Lattice Oxygen in Titania on Nanoporous Gold

Nanoporous gold modified by atomic layer deposition of titania was employed as a model, inverse supported precious metal catalyst to explore the oxidative reactivity of Au/TiO₂ catalysts. The catalyst material is active for oxidation of CO using O from the titania lattice, even at low temperatures. The reactive lattice oxygen available for oxidative reactions was formed by thermal activation, with the total oxidative reactivity of the material showing a strong dependence on the annealing temperature prior to CO exposure. Finally, reduction of the titania via CO oxidation can be reversed under relatively mild conditions by exposure to O₂, presenting a viable mechanism for CO oxidation in steady state catalytic conditions.