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采用球磨法制取了Au/Al_2O_3/Mn_2O_3催化剂,并对其进行了NO_x储存还原(NSR)性能研究。实验结果表明,Au担载量对该催化剂的低温NSR催化活性有很大的影响,随着Au担载量的增加,其NSR催化活性呈上升趋势:当Au担载量不高于1.0%(质量分数,下同)时,分散度高,与载体Al_2O_3、Mn_2O_3之间存在强的相互作用力,导致在150℃条件下Au的氧化物难以被还原成活性组分Au~0,所以没有活性;当Au担载量大于1.0%时,颗粒尺寸变大,与载体Al_2O_3、Mn_2O_3之间相互作用力变弱,使得Au的氧化物在150℃条件下较容易被还原成Au~0,所以活性得到显著提升。当Au担载量为2.0%时,NO_x转化率和N_2选择性分别能够达到49.6%和71.9%。
The Au / Al_2O_3 / Mn_2O_3 catalyst was prepared by ball milling method, and its NO_x storage reduction (NSR) performance was studied. The experimental results show that the Au loading has great influence on the low temperature NSR catalytic activity of the catalyst. With the increase of the Au loading, the NSR catalytic activity shows an upward trend: when the Au loading is not higher than 1.0% Mass fraction, the same below), the dispersion degree is high and there is a strong interaction force with the carriers Al 2 O 3, Mn 2 O 3 so that the oxide of Au is hard to be reduced to the active component Au 0 at 150 ° C, so there is no activity When the Au loading is more than 1.0%, the particle size becomes larger and the interaction force with the carriers Al 2 O 3 and Mn 2 O 3 becomes weaker, so that the oxide of Au is more easily reduced to Au 0 at 150 ° C. Therefore, the activity Have been significantly improved. When the Au loading is 2.0%, the NO_x conversion and N_2 selectivity can reach 49.6% and 71.9% respectively.