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jinkai838

木虫 (著名写手)

C-EPI: 4
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金币: 2004.5
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虫号: 499385
注册: 2008-02-10
性别: GG
专业: 计算机科学的基础理论

[交流] 【资源】95年JC中关于球磨制备Nanophase Fluorite-Structured CeO2–ZrO2 Catalysts的已有1人参与

The utilization of mechanical milling for the preparation of catalysts
based on ceria structurally modified with zirconia is presented.
It is shown that room-temperature high-energy ball milling is an effective
tool for the synthesis of nanophase CeO2–ZrO2 solid solution
in a wide composition range. The use of combined X-ray diffraction
analysis, Raman spectroscopy, and electron microscopy indicate
that the milling process induces the formation of true solid solutions
with a contraction of the cell parameter for cubic ceria following
the introduction of Zr into the lattice. This, in turn, remarkably enhances
the oxygen storage/transport and redox capacity compared
to pure ceria and zirconia or to a simple mixture thereof. An unusual
resistance to high-temperature cycling was also evidenced.
These features were analyzed by the study of the reduction profile
of doped ceria carried out by temperature-programmed reduction
at different milling times. The oxygen storage capacity (OSC) of the
catalysts was also evaluated; both the total and the kinetic accessible
OSC indicated that the best composition is CexZr1¡xO2 with
x>0.5. This was correlated to the structural features and to the
presence of a high concentration of ions with redox character (i.e.,
Ce4C ions) which favor oxygen mobility.
http://d.namipan.com/d/a88524bc3eab98b58ad79f504b239a4f7679b016b5e61200

[ Last edited by ^_^@^_^ on 2010-5-9 at 17:04 ]

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