Nanosized, Hollow, and Mn-Doped CeO2/SiO2 Catalysts via Galvanic Replacement: Preparation, Characterization, and Application as Highly Active Catalysts

We prepared 20–30 nm hollow CeO2 nanoparticles with 6–9-nm-thick porous shells by performing an easy, cost-effective, and water-based galvanic replacement on SiO2-supported Mn3O4 nanoparticles with Ce3+. The low-density, defected structure doped with residual Mn and the easily reducible surface makes the catalysts highly reactive for both CO oxidation and soot combustion reactions.