Highly Active CeO2 Nanocatalysts for Low-Temperature CO Oxidation

Abstract

Ceria (CeO₂) nanocatalysts were synthesized by three different methods via a simple sol–gel method (SGM), precipitation method (PPM), and solution combustion method (SCM) for CO oxidation reaction. The results show that the CeO₂ catalysts prepared by SGM possess small crystallite size (9 nm), more lattice defects (active sites), high specific surface area (188 m² g^–1), and better thermal stability. Raman spectra showed that large number oxygen vacancies were possessed by CeO₂-SGM catalysts as compared to CeO₂-PPM and CeO₂-SCM. It was observed that the catalytic activity for CO oxidation reaction is greatly influenced by the preparation method. The order of activity and stability of CeO₂ material prepared by different methods for CO oxidation process is as follows: CeO₂-SGM > CeO₂-PPM > CeO₂-SCM, respectively.