Inverse iron oxide/metal catalysts from galvanic replacement

Key chemical transformations require metal and redox sites in proximity at interfaces; however, in traditional oxide-supported materials, this requirement is met only at the perimeters of metal nanoparticles. We report that galvanic replacement can produce inverse FeO(x)/metal nanostructures in which the concentration of oxide species adjoining metal domains is maximal. The synthesis involves reductive deposition of rhodium or platinum and oxidation of Fe(2+) from magnetite (Fe(3)O(4)). We discovered a parallel dissolution and adsorption of Fe(2+) onto the metal, yielding inverse FeO(x)-coated metal nanoparticles. This nanostructure exhibits the intrinsic activity in selective CO(2) reduction that simple metal nanoparticles have only at interfaces with the support. By enabling a simple way to control the surface functionality of metal particles, our approach is not only scalable but also enables a versatile palette for catalyst design.