کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
62332 | 47634 | 2008 | 10 صفحه PDF | دانلود رایگان |

CeO2 and Ce–Zr mixed oxides with different Ce:Zr ratios were prepared; characterised by Raman spectroscopy, XRD, TEM, N2 adsorption at −196 °C, and H2-TPR; and tested for soot oxidation under NOx/O2. Among the different mixed oxides, Ce0.76Zr0.24O2 provided the best results. Ce0.76Zr0.24O2 presented greater activity than pure CeO2 for soot oxidation by NOx/O2 when both catalysts were calcined at 500 °C (soot oxidation rates at 500 °C are 14.9 and 11.4 μgsoot/s, respectively), and the catalytic activity of CeO2 decayed significantly with calcination temperature (from 500 to 1000 °C), whereas Ce0.76Zr0.24O2 presented enhanced thermal stability at temperatures as high as 1000 °C. In addition, Ce0.76Zr0.24O2 catalysed the reduction of NOx by soot at around 500 °C more efficiently than CeO2, thereby contributing to the decreased NOx emission level. The catalytic activity of CeO2 and Ce0.76Zr0.24O2 for soot oxidation by NOx/O2 depended on the textural properties (BET area; crystallite size), but other properties of the oxides, such as redox behaviour and/or enhanced lattice oxygen mobility, also played a significant role.
Journal: Journal of Catalysis - Volume 259, Issue 1, 1 October 2008, Pages 123–132