催化脱硝技术研究进展—催化剂的种类、制备方法及催化活性

随着工业及城市交通的发展,其所排放的NO和NO_2逐渐增多,由此导致的光化学烟雾、酸雨等大气污染问题愈加严重,与此同时,人类的身体健康也同样受到了威胁.据此, NO_x的消除成为当下的一个重要研究方向.目前NO_x的去除方法主要为选择性催化还原(SCR)去除方法,该法具有高效率的NO_x去除效果、高温度区间,较低的SO_2转化率等特点.催化剂在SCR反应中起着关键和核心作用, NO_x脱除效率的高低取决于催化剂的催化效率,如何提高催化剂的催化效率一直是研究者不断努力的目标.催化剂由载体和活性组分两大部分构成,载体的物质种类、活性组分的组成物质以及二者间的相互作用,是影响催化效率的主要因素.载体物质目前常用的主要是Al_2O_3、 SiO_2和TiO_2等金属氧化物,而活性组分则主要为Pd、 Pt、 Mn、 Ce、 V和W等,但目前应用较为广泛的活性组分主要为Mn、 Ce、 V和W等.研究开发新的载体物质及活性组分对催化脱硝技术的进步具有十分重要的意义.

Research Progress in Catalytic Denitrification Performance: The Catalyst Type, Preparation Methods and Activity

The emission of nitrogen oxides (NO and NO2) from coal fired power plants and automobiles is a serious concern due to their contribution to haze, photochemical smog and acid rain. The selective catalytic reduction of NOX with NH3 has been proved to be a mature technology for the removal of NOX. At present, metal oxides such as TiO2, Al2O3 and SiO2 are usually used as support material for SCR catalysts, which carry active components including Pt, Pd, Ce, V and W on the surface to achieve high activity of SCR. However, Pt and Pd not only belong to precious metals with high costs, but also can result in the non-selective oxidation of NH3 at high temperatures. Therefore, there are few applications in industry. Thus, non-precious metals Ce, V and W are widely used for the doping of active components. Accordingly, the research on the carrier and the active component has extremely important research significance.