Fe and Mn mixed oxide catalysts supported on Sn-modified TiO2 for the selective catalytic reduction of NO with NH3 at low temperature

FeMn/SnxTiO2 catalysts were synthesized by introducing Sn as an additive to modify TiO2 supports, and the Sn doping could improve the SO2 tolerance and low-temperature SCR activity significantly.

Study on the Mechanism of SO2 Poisoning of MnOx/PG for Lower Temperature SCR by Simple Washing Regeneration

Manganese oxide-supported palygorskite (MnOX/PG) catalysts are considered highly efficient for low-temperature SCR of NOx. However, the MnOX/PG catalyst tends to be poisoned by SO2. The effect of SO2 on activity of the SO2-pretreated poisoning catalysts under ammonia-free conditions was explored. It was determined that the MnOx/PG catalyst tends to be considerably deactivated by SO2 in the absence of ammonia and that water-washed regeneration can completely recover activity of the deactivated catalyst. Based on these results and characterizations of the catalysts, a reasonable mechanism for the deactivation of MnOx/PG catalyst by SO2 was proposed in this study. SO2 easily oxidized to SO3 on the surface of the catalyst, leading to the formation of polysulfuric acid, wrapping of the active component and blocking the micropores. The deactivation of the MnOx/PG catalyst is initially caused by the formation of polysulfuric rather than the deposition of ammonia sulfate, which occurs later.

Preparation of Cu-BTC Supported Fly Ash-Based Catalyst and Research on Low-Temperature SCR Denitration Performance

The novel Cu-BTC/FA materials were synthesized with Cu-BTC as the active component and solid fly ash as the catalyst carrier. then developed as the NO removing catalysts for low temperature selective catalytic reduction (SCR) with NH3. The physic-chemical properties of catalyst samples were characterized by multiple techniques, such as SEM, XRD, FTIR, XPS, TPR and Raman. The results show that: (1) The active component Cu-BTC loading ratio is 9%, the denitration performance is excellent and has strong stability. Under this condition, the catalyst showed the highest NH3-SCR activity, giving 94% NO conversion. (2) The catalysts show the good cyclic and stability in SCR denitration under 200 ℃. (3) It still shows high NO removal rate and good stability under the condition of SO2, and the denitration rate is as high as 78.36%. (4) There is a certain degree of resource integration for carrier fly ash, which not only treats air pollutants to a certain extent, but also achieves the purpose of solid waste recycling.