Thermally stable SBA-15 supported sub-2 nm gold clusters, highly active in room temperature CO oxidation: Effect of thermal pretreatment

摘要

Sub-2 nm gold clusters were prepared by adsorption of the [Au(en)(2)]Cl-3 complex on the SBA-15 mesoporous silica surface and proper thermal treatment. It has been shown that pre-treatment in hydrogen at 400-600 degrees C allows stabilizing gold clusters on the support, preventing their sintering during further treatment in oxygen up to 600 degrees C. The high activity of the Au/SBA-15 catalyst in a low-temperature CO oxidation (similar to 100% CO conversion at 25 degrees C), not typical for Au/SiO2 systems, is attributed to the extremely small size of gold particles. The mechanism of stabilization of gold clusters on the SBA-15 support is also discussed.