Fe/Al-PILC催化C_3H_6选择性还原NO的实验研究

采用浸渍法制备了负载于铝柱撑黏土的铁基催化剂(Fe/Al-PILC),在固定床反应器上测试其催化C3H6选择性还原NO的性能。通过N2吸附-脱附、X射线衍射(XRD)、H2的程序升温还原(H2-TPR)、紫外可见光谱(Uv-vis)、吡啶吸附红外光谱(Py-FTIR)等手段对催化剂的物理化学性质进行表征。结果表明,9Fe/Al-PILC在400-550℃能够还原98%以上的NO,而且SO2和水蒸气对其催化性能的影响很小。XRD、N2吸附-脱附表征结果表明,Fe/Al-PILC催化剂中铁氧化物高度分散在载体表面,催化剂有较大的比表面积和孔容。H2-TPR结果表明,催化剂的活性主要由Fe_2O_3物相的还原性能决定。Uv-vis结果表明,催化剂的活性与铁氧低聚物种FexOy呈正相关性。Py-FTIR结果表明,催化剂表面同时存在Lewis酸和Brnsted酸,L酸性位是NO和C3H6反应的主要催化活性中心。

Experimental study on selective catalytic reduction of NO with propene over iron based catalysts supported on aluminum pillared clays

Iron based catalysts supported on aluminum pillared clays (Fe/Al-PILC) was prepared by impregnation method and the selective catalytic reduction of NO with propene by the Fe/Al-PILC catalysts was investigated in a fixed bed reactor. The physical and chemical properties of the catalysts were characterized by N₂ adsorption/desorption, XRD, H₂-TPR, UV-Vis, Py-IR, etc. Results showed that 9% Fe/Al-PILC reduced 98% of NO at 400-550°C. SO₂ and water vapor slightly influenced the catalytic activity of the catalysts. XRD and N₂ adsorption/desorption characterization results revealed that the iron oxides in the catalyst were highly dispersed on the surface of the carrier and the catalyst has a large specific surface area and pore volume. H₂-TPR results indicated that the activity of the catalysts was mainly determined by the reduction performance of Fe₂O₃ phase. UV-Vis results showed that the activity of the catalysts was positively correlated with the iron oxide oligomer Fe_xO_y. Py-IR results indicated that both Lewis acid and Brønsted acid were formed on the catalyst surface and the Lewis acid sites were the main catalytic activity center of NO and C₃H₆ reaction.