甲醇裂解的创新实验

为了全面掌握流动法—甲醇裂解实验中催化剂的活性,采用浸渍法制备了Pd/CeO2-ZrO2(Pd/CZ)和Pd-Co/CeO2-ZrO2(Pd-Co/CZ)催化剂。运用X射线衍射、N2吸附-脱附、储氧量测定、CO化学吸附、H2程序升温还原(H2-TPR)和X射线光电子能谱对催化剂进行了表征,考察了其催化甲醇裂解反应活性。结果表明,Co的添加不仅提高了催化剂的储氧性能,而且大大提高了催化剂活性组分的分散程度,同时,使得金属和载体间相互作用增强,增加了Pd周围的电子密度,使Pd保持在部分氧化状态Pdδ+(0δ2),进而提高了甲醇催化裂解反应的活性,280℃时甲醇能达到完全裂解,实验效果得到明显改善。

Innovative Experiment Design for Methanol Decomposition

In order to fully grasp the flow method - the catalytic activity for methanol decomposition, CeO2 -ZrO2 supports were pre- pared by the coprecipitation method and were loaded with Pd or Pd and Co by impregnation to form Pd/CeO2 -ZrO2 （Pd/CZ） and Pd -Co/CeO2 -ZrO2 （Pd -Co/CZ） catalysts. The catalysts were characterized by X -ray diffraction, low temperature N2 adsorptionde- sorption, oxygen storage capacity, CO chemisorption, H2 temperature - programmed reduction （ H2 - TPR） and X - ray photoelectron spectroscopy （XPS）. The results showed that the addition of cobalt did not only improve the oxygen storage capacity of the catalyst, but also greatly improve the degree of dispersion of Pd. The addition of cobalt faintly improved the catalytic activity for methanol decomposition. Over Pd - Co/CZ catalyst, a 90% conversion of methanol can be achieved at around 280℃, which is about 20℃ lower than the temperature needed for Pd/CZ. It also enhanced the metal - support interaction and increased the electronic surroundings of Pd sites, which maintained Pd in a partly oxidized （Pdδ＋ ） state and consequently increased the activity for methanol decomposition according to H2 - TPR and XPS measurements. This innovative experiment plays an active role in enhancing the effect of the experiment.