Based on the density functional theory, the adsorption processes of NH₃, and NO and O₂ on the Mn active sites of MnO_x/SiO₂ β-cristobalite (101) surface were simulated. The results show that NH₃, NO and O₂ can be effectively adsorbed on the Mn active sites of both MnO₂/SiO₂ β-cristobalite (101) and Mn₂O₃/SiO₂ β-cristobalite (101) surface. The adsorption characteristics of the two catalysts are different. The adsorption energy of NH₃ molecule on the MnO₂/SiO₂ β-cristobalite (101) surface is much higher than that on the Mn active sites of Mn₂O₃/SiO₂ β-cristobalite (101) surface. The NO molecule and the O₂ molecule are a little easier to be adsorbed on the Mn active sites of Mn₂O₃/SiO₂ β-cristobalite (101) surface. The large difference of NH₃ adsorption energy between the two catalysts becomes one of the main reasons why MnO₂/SiO₂ has better catalytic activity than Mn₂O₃/SiO₂. Furthermore, the high adsorption energy of NH₃ on MnO₂/SiO₂ surface proves that SiO₂ is an excellent carrier and MnO₂/SiO₂ catalyst is an outstanding NH₃-SCR catalyst at low temperature.

基于密度泛函理论上，NH的吸附过程₃，和NO和O ₂上的MnO中的Mn的活性部位_X /二氧化硅₂ β方晶石（101）表面进行了模拟。结果表明，NH ₃，NO和O ₂可以有效地吸附在两者的MnO中的Mn的活性位点₂ /的SiO ₂ β方晶石（101）和Mn ₂ ö ₃ /二氧化硅₂ β方晶石（101）表面。两种催化剂的吸附特性不同。NH ₃分子在MnO ₂ / SiO ₂上的吸附能β方晶石（101）表面上超过了Mn的Mn类活性位点高得多₂ ö ₃ /二氧化硅₂ β方晶石（101）表面。的NO分子和O ₂分子更容易一点被吸附在Mn的Mn类活性位点₂ ö ₃ /二氧化硅₂ β方晶石（101）表面。两种催化剂之间的NH ₃吸附能差异很大，成为MnO ₂ / SiO ₂具有比Mn ₂ O ₃ / SiO ₂更好的催化活性的主要原因之一。此外，NH ₃对MnO的高吸附能₂ / SiO ₂表面证明，在低温下，SiO ₂是优良的载体，而MnO ₂ / SiO ₂催化剂是优良的NH ₃ -SCR催化剂。