原位拉曼和红外技术对二氧化铈脱硝催化剂硫酸化处理过程的研究

Investigation of CeO_2 deNOx catalyst in the sulfation process by in situ Raman and DRIFTS spectroscopy

NH_3选择性催化还原NOx技术的关键是催化剂,其中,理解催化剂的硫中毒机制是获取抗硫中毒催化剂的有效方法。借助原位拉曼和红外表征考察氧化态、还原态CeO_2催化剂在二氧化硫、氧气处理气氛中体相和表面硫酸盐以及氧缺陷的变化。NH_3-SCR催化反应结果表明,硫酸化还原态CeO_2具有较优的脱硝性能,这主要来源于还原态CeO_2上的缺陷,有利于氧化SO_2,产生表面硫酸盐,增强催化剂酸性,同时抑制体相硫酸盐的生成,促进NH_3-SCR反应的进行。

The key to NH3-selective catalytic reduction of NOx（ NH3-SCR） is catalyst. Understanding the mechanism of sulfur poisoning is an effective method to obtain the catalyst with good sulfur resistance.With the help of in situ Raman and DRIFTS characterization,oxidized and reduced CeO2 catalysts treated under the condition of SO2 and O2atmosphere were investigated in order to determine their bulky and surface changes of sulfates and oxygen defects. The catalytic results showed that the sulfated reduced CeO2 catalyst had better denitrification performance due to the defects of reduced CeO2 sample,which was beneficial to the oxidation of SO2,generation of surface sulfate and the enhancement of catalyst acidity,and then inhibited the generation of bulky sulfate and promoted the process of NH3-SCR reaction.