Facile Synthesis of MnO.sub.2@SiO.sub.2/Carbon Nanocomposite-based Gold Catalysts from Rice Husk for Low-Temperature CO Oxidation

Herein, MnO.sub.2@SiO.sub.2/C was produced from rice husk derived SiO.sub.2/carbon composite and MnO.sub.2 via hydrothermal method. The nanostructure gave good microstructural, morphological properties with highly catalytic properties. The hybrid catalyst comprising of MnO.sub.2@SiO.sub.2/C nanocomposite-supported gold nanoparticles was successfully fabricated by the novel solid grinding and tested for CO oxidation's application. MnO.sub.2 nanoballs are 5 - 8 nm in diameter with a shell thickness of 1 nm, packing with laminar [MnO.sub.6] unit cells. The as-prepared gold catalysts containing 2wt% of Au loading, exhibited 50% CO conversion and a high specific activity of 0.21 mol.sub.CO g.sub.Au.sup.-1 h.sup.-1 at 38 °C.