Magnetically Recoverable Catalysts using Hierarchical Magnetite/Silica Nanoassemblies as Supports Yadong Yin, Department of Chemistry, University of California, Riverside, CA 92521 Recoverable catalysts: We aim to develop a general method for protecting supported metal nanocatalysts from coagulation while at the same time maintaining their high catalytic activity. We have developed a process for the fabrication of mesoporous silica protected core-satellite nanocomposite catalysts through a series of simple sol-gel and surface-protected etching processes. It has been an important challenge to improve the stability, recyclability, and catalytic selectivity of metal nanocatalysts. We have developed a general “encapsulation and etching” approach for stabilizing metallic nanocatalysts and making them accessible for reactants. A “surface-protected etching” strategy has been used for creating mesoporous structures in the outer oxide shell, thus allowing controllable mass transfer during catalytic reactions. We have also incorporated superparamagnetic cores to the composite structures to form magnetically recyclable catalysts for liquid-phase reactions. The next goal is to extend this type of nanocatalysts for gas phase reactions.