Abstract

An Au/Fe₃O₄ nanocomposite catalyst was fabricated through a simple deposition–precipitation method. The Au/Fe₃O₄ nanocomposite is a true nanocomposite that has single crystalline Au nanoparticles supported on single crystalline Fe₃O₄ nanoparticles. Lattice fringes from both Au and Fe₃O₄ single nanoparticles were simultaneously observed by transmission electron microscope (TEM). This nanocomposite catalyst showed much high activity in low temperature CO oxidation reaction. The Au/Fe₃O₄ nanocomposite catalyst reaches 100% CO conversion at 40 °C. In comparison, Au/commercial Fe₃O₄ catalyst needs 375 °C to convert CO. This Au/Fe₃O₄ nanocomposite is an ideal sample to study synergetic effect between the catalyst and the support at nanoscale.