A spherical, disordered, wormhole-like nanocomposite, consisting of 115 nm diameter MCM-41 particles containing 3 nm diameter Pt nanoparticles (see Figure), is described. A surfactant that stabilizes and prevents aggregation of the Pt nanoparticles during synthesis is removed by calcination, resulting in a high Pt catalytic surface area. Multiple cycles of cinnamic acid hydroglenation at room temperature demonstrate the potential of this reusable catalytic nanocomposite.