CexTi1-xO2 mixed oxides of different mole ratios (x=0, 0.1, 0.2～0.9, 1.0) were prepared by co-precipitation of TiCl4 with Ce(NO3)3 and then loaded with different amounts of CuO. The effects of CuO on NO+CO reaction were investigated, and the structure and reductive properties of various CuO/CexTi1-xO2 were characterized by the methodologies of BET, TPR and XRD. The results show that different Ce/Ti mole ratios and calcination temperatures induce changes of structure and reductive properties of the CexTi1-xO2 mixed oxides. When x=0.1～0.5, amorphous CeTi2O6 phase mainly forms at 650 ℃ compared to the formation of CeTi2O6 which crystallizes at 800 ℃. When x＞0.6, some TiO2 enters the CeO2 lattice and a CeO2-TiO2 solid solution is formed. The activity of 6%CuO/CexTi1-xO2 calcined at 650 ℃ is largely affected by the x values, which is the highest when x=0.3, 0.4 and 0.9. The NO conversion reaches 70% at a reaction temperature of 150 ℃. By comparison, the x values have little effect on the activity of 6%CuO/CexTi1-xO2 calcined at 800 ℃. There are strong interactions between CuO and CeTi2O6, I.e., formation of the CeTi2O6 phase shifts the CuO reduction peak temperature from 380 to 200 ℃, and CuO, in turn, shifts the CeTi2O6 reduction peak temperature from 600 to 300 ℃.
参考文献
| [1] | Mitome J;Aceves E;Ozkan U S .Role of lanthanide elements on the catalytic behavior of supported Pd catalysts in the reduction of NO with methane[J].Catalysis Today,1999,53:597. |
| [2] | Rosynck M P .Catalytic properties of rare earth oxides[J].Journal of Catal Rev Sci Eng,1977,16(01):111. |
| [3] | Trovarelli A;Leitenburg C D;Boaro M et al.The utilization of ceria in industrial catalysis[J].Catalysis Today,1999,50:353. |
| [4] | Hori C E;Permana H;Simon Ng K Y et al.Thermal stability of oxygen storage properties in a mixed CeO2-ZrO2 system[J].Applied Catalysis B:Environmental,1998,16:105. |
| [5] | Larsson PO.;Andersson A. .Complete oxidation of CO, ethanol, and ethyl acetate over copper oxide supported on titania and ceria modified titania[J].Journal of Catalysis,1998(1):72-89. |
| [6] | Monte R D;Fornasiero P;Kaspar J et al.Pd/Ce0.6Zr0.4O2/Al2O3 as advanced materials for three-way catalysts[J].Applied Catalysis B:Environmental,2000,24:157. |
| [7] | Francisco M S P;Mastelaro V R;Nascente P A P et al.Activity and characterization by XPS, HR-TEM, Raman Spectroscopy, and BET surface area of CuO/CeO2-TiO2[J].Journal of Physical Chemistry B,2001,105:10515. |
| [8] | Masui T.;Peng YM.;Sakata T.;Machida K.;Mori H.;Adachi G.;Fujiwara K. .Characterization and catalytic properties of CeO2-ZrO2 ultrafine particles prepared by the microemulsion method[J].Journal of Alloys and Compounds: An Interdisciplinary Journal of Materials Science and Solid-state Chemistry and Physics,1998(1/2):116-122. |
| [9] | Vidal H. .Redox behavior of CeO_2-ZrO_2 mixed oxides I.Influence of redox treatments on high surface area catalysts[J].Applied Catalysis, B. Environmental: An International Journal Devoted to Catalytic Science and Its Applications,2000(1):49-63. |
| [10] | Rynkowske J;Farbotko J;Touroude R et al.Redox behavior of ceria-titania mixed oxides[J].Applied Catalysis A:General,2000,203:355. |
| [11] | von Rottkay K.;Rubin M.;Slack J.;Kullman L.;Richardson T. .Influence of stoichiometry on electrochromic cerium-titanium oxide compounds[J].Solid state ionics,1998(Special Issue SI):425-430. |
| [12] | Purans J;Azens A;Granqvist C G .X-ray absorption study of Ce-Ti oxide films[J].Electrochimica Acta,2001,46:2055. |
| [13] | Luo M F;Chen J;Chen L S .Structure and redox properties of CexTi1-xO2 solid solution[J].Chemistry of Materials(in Chin),2001(13):197. |
| [14] | Wang X Y;Wan Y;Lu G Z .Effect of lanthanum on methanol fuel exhoust deep oxidation over palladium catlayst[J].Journal of Rare Earths,2003,21(01):51. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%