Controlled Synthesis And Properties Of CeO₂Micro/nanostructures

Cerium dioxide (CeO2) has been used in many fields including optical film, polishing materials, gas probes, etc. for its unique physical chemical nature. At the same time, CeO2also can be used in catalysis, fuel cell and other emerging fields because of the ability of the storage of oxygen performance by Ce3+<——>Ce4+transformation. A hot spot of the current study is the development of new methods to synthesize cerium oxide micro/nano materials, which is mild, simple and morphology controlled. The significance of this paper is controlled-synthesis of CeO2micro/nanostructures. Various morphologies of CeO2micro/nanostructures such as rod, sphere, cluster and tube have been successfully synthesized by solvent-assisted method and ion exchange route. We studied the luminescent properties and H2-TPR of CeO2products, the practical application of doped-ceria used in the heavy oil additives is also studied.The concrete researches are as follows:(1) Solvent assisted morphology-controlled synthesis of CeO2micro/nanostructures and its luminescent properties. Cerium oxide particles was prepared by urea hydrolysis. Rod-like cerium oxide with a length of1～2μm and cluster-like cerium oxide with a diameter of about2μm were obtained by changing the solvent and the concentration; we investigated the influence of synthesis factors on the morphology of the products. The CeO2with sphere and cluster morphology were obtained by solvent thermal reaction of ethanol and n-hexane, respectively. And the luminescence properties of the preparation of CeO2:Eu3+micro/nanostructures were studied.(2) Ion exchange route to synthesize CeO2micro/nanotubes and its luminescent properties. CeO2micro/nanotubes with the wall thickness of about50nm, the diameter of2-3μm and the length of about20μm were successfully synthesized by a solution-phase ion exchange process using MgCO3·3H2O as templates. And the method is extended to be applied to preparation of other rare earth micro/nanotubes. We investigated the influence of temperature and solvent on the morphology of the products. The luminescence properties of CeO2:Eu3+micro/nanotubes was also studied.(3) Transition metal doped morphology-controlled synthesis of CeO2and its performance. We studied the influence of zirconium, copper, manganese and cobalt doping on the morphology and performance of the CeO2micro/nanostructures, we found that the cobalt, manganese, zirconium can enhance the interaction of H2and oxygen of cerium oxide surface and lattice oxygen; the temperature of H2-TPR of the products can be reduced by doping copper. On this basis, the samples were surface modified, and the calorific value analysis of heavy oil added with products was also studied.