具有球形催化界面的MnCeOx/P84催化滤布的NOx脱除性能

催化滤布可同时去除烟气中的粉尘颗粒和NO_x,满足水泥等行业NO_x脱除的迫切需求。而催化滤布中催化界面的形貌会显著影响其脱硝性能。制备了具有球形催化界面的MnCeO_x/P84催化滤布(α-MnCeO_x/P84),并考察其NO_x脱除性能。结果表明:当MnCeO_x负载量为60 g/m2时,α-MnCeO_x/P84在130 ℃时NO_x脱除率为86.9%,160~190 ℃时NO_x脱除率>97%。同时,α-MnCeO_x/P84具有较好的抗SO₂性能和稳定性,通入体积分数为0.003%的SO₂后,在190 ℃下,其NO_x脱除率达到83%左右;停止通入SO₂后,α-MnCeO_x/P84的NO_x脱除率上升并稳定在93%左右。且经过200 h的脱硝反应测试后,α-MnCeO_x/P84的脱硝活性与催化剂负载量未下降。表征分析结果表明,α-MnCeO_x/P84中球形MnCeO_x活性组分以弱结晶形式存在,紧密地包裹在滤料纤维表面,且分散均匀;中孔是MnCeO_x催化剂的主要孔结构,能够为催化反应的进行提供通道。H₂-TPR与Insitu DRIFTS分析进一步表明,α-MnCeO_x/P84在100~200 ℃有良好的氧化还原能力,且具有丰富的Lewis和Brnsted酸位,为其优越的低温NH₃-SCR脱硝性能提供了重要保障。具有球形催化界面的MnCeO_x/P84催化滤布具有低负载量、高稳定性的特点,为滤料除尘脱硝技术的推广应用提供参考。

REMOVAL PERFORMANCE OVER MnCeOx/P84 CATALYTIC FILTER WITH SPHERICAL CATALYTIC INTERFACE

Catalytic filters are low-cost and high-efficiency for synergistic removal of NO_x and particulates, which have become the development direction of air pollution control technology in the cement and steel industries. The morphology of the catalytic interface in the catalytic filter has a significant influence on its denitration performance. MnCeO_x/P84 catalytic filter with a spherical catalytic interface (α-MnCeO_x/P84) was prepared, and its NO_x removal performance was investigated. The results showed that the NO_x removal efficiency of α-MnCeO_x/P84 was 86.9% at 130 ℃ and 97% above at 160 ℃ to 190 ℃ when the MnCeO_x loading was 60 g/m2. At the same time, α-MnceO_x/P84 had good SO₂ resistance and stability, and the NO_x removal rate of α-MnceO_x/P84 could reach 83% at 190 ℃ after introducing SO₂ with a volume fraction of 0.003%. When the injection of SO₂ was stopped, NO_x removal rate of α-MnceO_x/P84 increased and stabilized at about 93%. After 200 hours denitrification reaction test, the denitrification efficiency and catalyst loading of α-MnCeO_x/P84 did not decrease significantly. The characterization results showed that the spherical MnCeO_x active component in α-MnCeO_x/P84 was present in weak crystalline form, tightly wrapped around the surface of the filter fiber, uniformly dispersed, and the mesopore was the main pore structure of the MnCeO_x catalyst, which could provide a channel for the catalytic reaction to proceed. Further analysis of H₂-TPR and In-situ DRIFTS showed that α-MnCeO_x/P84 had good redox ability at 100 ℃ to 200 ℃ and had abundant Lewis acid sites and Brnsted acid sites, which provided an important guarantee for its superior low-temperature NH₃-SCR denitrification performance. MnCeO_x/P84 catalyst filter with a spherical catalytic interface had the characteristics of low load and high stability, which laid a foundation for the promotion and application of dust and NO_x removal over catalytic filters.