Room-temperature CO oxidation over a highly ordered mesoporous RuO2 catalyst

Highly ordered mesoporous ruthenium dioxide (meso-RuO2) has been successfully synthesized by controlling the surface hydrophobicity of a mesoporous silica template (KIT-6) via a nano-replication method. The meso-RuO2 material, thus obtained, exhibits a well-defined mesostructure and high surface area (131 m2 g−1). The physicochemical properties of the meso-RuO2 material are characterized by electron microscopy, X-ray diffraction, N2 adsorption–desorption, temperature programmed techniques, and X-ray photoelectron spectroscopy. Pretreatment of the meso-RuO2 catalyst under different gas environments (O2, H2 and CO) strongly affects the catalytic activity towards CO oxidation. The meso-RuO2, pretreated by O2 flowing at 200 °C, exhibited excellent catalytic activity for CO oxidation, 100% CO conversion with long-term stability at room temperature, whereas the meso-RuO2 catalysts with pretreatment under other conditions are not very active at room temperature. It is found that the surface oxygen species generated on the meso-RuO2 during O2 pretreatment at 200 °C provide CO oxidation activity at room temperature.