State Key Laboratory of Silicon Materials, Department of Materials Science and Engineering, Zhejiang University, Zheda Road 38, Hangzhou 310027, China.
J Hazard Mater. 2011 Apr 15;188(1-3):105-9. doi: 10.1016/j.jhazmat.2011.01.078. Epub 2011 Jan 26.
MnO(2) nanotubes, nanorods, and nanoparticles were prepared using a hydrothermal method, after which the different activities for selective catalytic reduction (SCR) of nitrogen oxides (NO(x)) were compared. MnO(2) nanorods performed the highest activity for reduction of NO(x) under a gas hourly space velocity of 36,000 h(-1) with conversion efficiencies of above 90% between 250 and 300 °C; it also had the highest removal efficiency of 98.2% at 300 °C. From the analysis of X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, temperature-programmed desorption, and temperature-programmed reduction, we can ascribe the high activity of MnO(2) nanorods to low crystallinity, more lattice oxygen, high reducibility, and a large number of strong acid sites. The apparent activation energy of the SCR reaction on the surface of nanorods was calculated to be 20.9 kJ/mol, which favored the reaction better than the other catalysts.
采用水热法制备了 MnO(2) 纳米管、纳米棒和纳米颗粒，并比较了它们在选择性催化还原（SCR）氮氧化物（NO(x)）方面的不同活性。在气体时空速度为 36000 h(-1)的条件下，MnO(2) 纳米棒在 250 至 300°C 之间表现出最高的 NO(x)还原活性，转化率超过 90%；在 300°C 时，其去除效率也高达 98.2%。通过 X 射线衍射、扫描电子显微镜、X 射线光电子能谱、程序升温脱附和程序升温还原分析，我们可以将 MnO(2) 纳米棒的高活性归因于低结晶度、更多的晶格氧、高还原性和大量的强酸位。纳米棒表面 SCR 反应的表观活化能计算为 20.9 kJ/mol，这比其他催化剂更有利于反应。
