典型SCR脱硝催化剂钾中毒特征研究

以钾为代表的碱金属元素是引发SCR催化剂中毒的主要来源，通过浸渍法制备钾中毒催化剂，比较钾盐种类和钾盐浓度对催化剂脱硝活性的影响。结果表明，随着钾盐浓度的增加，催化剂比表面积下降，并出现板结现象；在KNO3、K2SO4和KCl钾盐中，同浓度下KCl造成的催化剂失活最严重。钾中毒对催化剂孔径结构和V2O5在载体TiO2上的分散度影响不显著；催化剂吸附表面因中毒会有粒子积聚成团，从而增大催化剂表面粗糙度；同时，钾中毒导致催化剂表面酸性位点的毒害，与新鲜催化剂相比，中毒后催化剂表面总酸量下降约62%。

Study of typical K-deactivation properties of SCR catalyst

Potassium is one of the typical alkali metals which results in catalyst deactivation of SCR system. K-deactivation catalysts were prepared by the impregnation method in this paper. The influence of the kinds and concentrations of sylvite on the activity of SCR catalysts was investigated. The results showed that with the increase of K ~ concentration, the specific surface area of the catalysts decreased. The compaction phenomenon of the catalyst appeared. The catalyst deactivation caused by KC1 was the most serious under the same concentration of KNO3, K2SO4 and KC1. K-deactivation had no significant impact on the pore structure of the catalyst and the dispersion of V205 on TiO2 carrier. Some particles accumulated on the adsorption surface of the catalyst due to K-deactivation effect which increased the surface roughness of the catalyst Meanwhile, K-deactivation resulted in the decrease of total amount of surface acid by about 62% on the deactivation catalyst compared with the fresh one.