Synthesis of CeO₂‐Based Quantum Dots through a Polyol‐Hydrolysis Method for Fuel‐Borne Catalysts

Abstract

Abstract The transparent colloidal solutions of monodisperse CeO 2 ‐based quantum dots (QDs) were prepared by heating a triethylene glycol (TEG) solution of Ce(NO 3 ) 3 ⋅6 H 2 O (and Fe(NO 3 ) 3 ⋅9 H 2 O) at 180 °C. The CeO 2 ‐based QDs were characterized by X‐ray powder diffraction (XRD), dynamic light scattering (DLS), transmission electron microscopy (TEM), UV/vis absorption spectra and Brunauer–Emmett–Teller (BET) surface area. CeO 2 ‐based QDs with uniform particle size below 5 nm exhibit narrow size distribution, quantum effect, good re‐dispersion ability and high surface area. For the formation of these QDs, a polyol‐hydrolysis mechanism is proposed. CeO 2 QDs are applied in fuel borne catalysts (FBCs) for diesel soot combustion, which exhibit excellent activity at a rather low temperature, owing to the homogeneous and large number of contact points between the catalyst and the soot. The doping with Fe can further improve the selectivity to CO 2 .