Mn/USY分子筛催化剂低温SCR脱硝性能

以USY分子筛为载体，采用等体积浸渍法制备了不同Mn负载量的Mn/USY催化剂。借助BET、XRD、SEM和FT-IR等手段，考察了催化剂的物相结构及脱硝活性。在90~210 ℃温度范围内，随着反应温度的升高，NO转化率逐渐提高，脱硝效率在210 ℃达到50%以上，其中10 Mn/USY的NO转化率高于其他几组催化剂。通过SEM和BET结果可以看出，Mn/USY分子筛催化剂的比表面积随着Mn负载量的增加而减少。新鲜的催化剂颗粒分散均匀，呈松散的堆叠状态，H2O和SO2实验后催化剂分散程度降低，比表面积、孔径和孔体积都有所下降。XRD结果表明，10 Mn/USY催化剂中MnO2的晶体特征峰最为明显，除此之外没有发现其他Mn或MnOx衍射峰。FT-IR分析结果表明金属Mn的负载并未对USY分子筛的内部结构造成破坏。

Selective catalytic reduction of NO with NH3 over Mn/USY catalysts at low temperature

A series of Mn/USY catalysts with different Mn loading amounts were prepared by the impregnation method. The catalysts were characterized using BET, XRD, SEM, and FT-IR. The conversion of NO was increased with temperature in the range 90-210℃, and the highest conversion was over 50% at 210℃. In particular, 10 Mn/USY achieved higher activity than did the other groups. BET and SEM experiments showed that the specific surface area was reduced with increase of Mn loading. SEM observation revealed that the catalyst particles were evenly distributed and loosely deposited. However, after the H2O and SO2 resistance tests, the specific surface area, pore size, and pore volumes of catalysts were decreased. XRD results further presented that the characteristic peaks of MnO2 were obvious at 10 Mn/USY, but there was no other diffraction peak. The FT-IR experiment shows that the USY structure was not damaged by loading Mn or MnOx.