Partial oxidation of methanol over copper catalysts supported on rice husk ash
Partial oxidation of methanol over copper catalysts supported on rice husk ash
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DOI：
10.1016/j.molcata.2009.11.005
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发表时间：
2010-03
影响因子：
--
通讯作者：
Wun-Syong Chen;F. Chang;L. S. Roselin;Ti-Cheng Ou;S. Lai
中科院分区：
文献类型：
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作者：
Wun-Syong Chen;F. Chang;L. S. Roselin;Ti-Cheng Ou;S. Lai
考察了以稻壳灰为载体的铜催化剂对甲醇部分氧化制氢的催化性能。采用沉积-沉淀法制备了催化剂，并用电感耦合等离子体原子发射光谱、热重分析、X射线衍射、程序升温还原、X射线光电子能谱和N2O滴定等技术对催化剂进行了表征。在673K焙烧条件下，铜负载量为10.2wt.%的催化剂具有较高的铜分散度和较小的铜颗粒尺寸。该催化剂对聚甲醛合成氢气具有较高的活性和选择性。O2分压对产物分布起着重要的决定作用。不同反应温度下催化剂的催化活性表明，CH3OH转化率、H_2选择性和CO选择性随反应温度的升高而增加。在不同温度下，POM可能参与了甲醇燃烧、甲醇水蒸气重整、甲醇分解、水煤气变换以及CO和H_2的氧化等反应。比较了两种催化剂的催化活性，结果表明，催化剂失活时间长，失活速度快，具有较高的CO选择性。这证明了Cu/RHA催化剂具有良好的热稳定性和POM制氢的选择性。
Copper catalysts supported on rice husk ash (Cu/RHA) were tested for partial oxidation of methanol (POM) to produce H2. The catalysts were prepared by deposition–precipitation and characterized by ICP-AES, TGA, XRD, TPR, XPS and N2O titration techniques. The Cu/RHA catalyst with 10.2wt.% Cu loading and under 673K calcination has higher copper dispersion and smaller Cu particle size. This catalyst exhibits higher activity and selectivity for POM to produce H2. The partial pressure of O2plays an important role to determine the product distribution. Catalytic activity of the catalyst at different reaction temperatures shows that CH3OH conversion, H2selectivity and CO selectivity increase with rise in temperature. At different temperatures along with POM, several reactions such as methanol combustion, steam reforming of methanol, methanol decomposition, water gas shift and oxidation of CO and H2might be involved. Comparison of catalytic activity of Cu/RHA and Cu/SiO2catalysts demonstrates that Cu/SiO2catalysts deactivate with time with faster rate and have higher CO selectivity. This proves that Cu/RHA catalysts have good thermal stability and selectivity for POM to produce H2.