摘要
采用溶胶凝胶法(sol-gel)制备了一系列以TiO2-SiO2复合氧化物为载体的锰铈氧化物催化剂,研究了SiO2的加入对钛基锰铈氧化物选择性催化还原(SCR)催化剂活性和选择性的影响,采用X射线衍射(XRD)、氨气程序升温脱附(NH3-TPD)和原位漫反射傅立叶变换红外光谱(in situ DRIFTS)等表征手段,分析了催化剂的物理与化学性能,并对催化剂SCR反应机理进行了初步探讨,研究结果表明,在TiO2中添加适当比例的SiO2能增加催化剂的比表面积和总孔容,从而提高活性元素在载体表面的分散度,并能提高催化剂表面的酸性,使得催化剂的转化效率有所提高,原位分析表明,吸附于Lewis酸性位上的配位态NH3物种和桥式硝酸盐为主要的活性反应物种。
A series of Manganese-Cerium oxide catalysts supported on the TiO2-SiO2 composite oxides were prepared by sol-gel meth- od. The DeNOx efficiency and selectivity of these catalysts modified with SiO2 addition was evaluated. The physico-chemical properties and the SCR reaction mechanism of these catalysts were characterized by the means of X-ray diffraction （XRD）, Temperature Pro- grammed Desorption （NH3-TPD） and in situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy （ in situ DRIFTS）. The ex- periment results show that when proper addition of SiO2 is added into TiO2 , the specific surface area and the overall pore volume of the catalysts were increased, the surface acidity of the catalyst was enhanced and the active element dispersion on the carrier was promo- ted, which contributed to the promotion of the DeNO~ efficiency of these catalysts in general. The situ DRIFTS studies reveal that the coordinated NH3 species adsorbed on the Lewis acid sites and bridged nitro-nitrato species are key active reactants.
出处
《现代车用动力》
2013年第1期35-42,共8页
Modern Vehicle Power
基金
国家自然科学基金资助项目(51176118)
作者简介
钟柳成（1989-），男，湖北省荆州市人，硕士研究生，主要研究方向为柴油机尾气后处理。
