Iron-based catalysts are nontoxic and have outstanding medium-temperature activity, which are considered as potential catalysts for the selective catalytic reduction of NO_x with NH₃ (NH₃-SCR). In this work, Fe (0.2)-W (0.05)-Ti catalyst prepared by deposition–precipitation exhibited over 90% NO_x conversion within the range of 280–420 °C and excellent resistance to SO₂ or H₂O. The excellent catalytic performance was due to the high proportion of Fe²⁺/(Fe²⁺ + Fe³⁺) and O_ads/(O_ads + O_lat) ratio and abundant surface acid sites. However, the catalyst lost part low-temperature catalytic performance after hydrothermal aging at 670 °C for 64 h. The surface area, proportion of Fe²⁺/(Fe²⁺ + Fe³⁺) and O_ads/(O_ads + O_lat) decreased significantly after aged. As a result, the lack of sufficiently active site to produce NO₂ resulted in the significant decrease for NO_x conversion at low-temperature section. Simultaneously, the decline of the surface acidity, especially the strong acid, meant that the adsorption capacity of the catalyst under high temperature weakened and the NO conversion corresponding declined.

铁基催化剂是无毒的，并且具有出色的中温活性，其被认为是潜在的催化剂的选择性催化还原的NO _X与NH ₃（NH ₃ -SCR）。在这项工作中，铁（0.2）-W（0.05）-Ti催化剂制备表现出超过90％的NO沉积-沉淀_X的280-420℃的范围内和优异的耐内转化成SO ₂或H ₂ O的优良催化性能是由于Fe ²⁺ /（Fe ²⁺ + Fe ³⁺）和O _ads /（O _ads + O _lat）比率和丰富的表面酸性位。但是，在670°C水热老化64 h后，催化剂失去了部分低温催化性能。老化后，表面积，Fe ²⁺ /（Fe ²⁺ + Fe ³⁺）和O _ads /（O _ads + O _lat）的比例显着降低。结果，缺乏足够的活性位点以产生NO ₂导致低温段的NO _x转化率显着降低。同时，表面酸度，特别是强酸的下降，意味着催化剂在高温下的吸附能力减弱，NO转化率相应下降。