The present invention provides a core-shell nanoparticle that includes a metal-oxide shell and a nanoparticle. Pores extend from an outer surface to an inner surface of the shell. The inner surface of the shell forms a void, which is filled by the nanoparticle. The pores allow gas to transfer from outside the shell to a surface of the nanoparticle. The present invention also provides a method of making a core-shell nanoparticle includes forming a metal-oxide shell on a colloidal nanoparticle, which forms a precursor core-shell nanoparticle. A capping agent is removed from the precursor core-shell nanoparticle, which produces the core-shell nanoparticle. The present invention also provides a method of using a nanocatalyst of the present invention includes providing the nanocatalyst, which is the core-shell nanoparticle. Reactants are introduced in a vicinity of the nanocatalyst, which produces a reaction that is facilitated or enhanced by the nanocatalyst.
STATEMENT OF GOVERNMENT SUPPORT
 This invention was made with government support under Contract No. DE-AC02-05CH11231 awarded by the U.S. Department of Energy. The government has certain rights in this invention.