在O2和NO存在下Ir催化氧化黑烟的研究

摘要

模拟柴油机尾气中O2和NO的氛围,研究了以Ir为基础的催化剂对黑烟的催化氧化.与Pt/SiO2比较,Ir/SiO2对黑烟氧化有其相似的催化活性,但有更高的CO选择性.通过测定Ir含量对催化活性和CO选择性的影响,发现在研究的范围内(0到5%),随着Ir含量的增加,催化活性增加, CO选择性降低.此外,测定了氧化物载体对催化活性及CO选择性的影响,得到了催化活性顺序为Ir/ZSM-5 ＞ Ir/SiO2 ＞ Ir/γ-Al2O3, CO选择性顺序为 Ir/ZSM-5 ＜ Ir/γ-Al2O3 ＜ Ir/SiO2.%The soot oxidation with Ir-based catalysts was investigated using simulated diesel exhaust gases. By comparing with Pt/SiO2, Ir/SiO2 showed similarly catalytic activity and high CO selectivity. The effect of Ir content on the catalytic activity and CO selectivity was examined. With the increasing of Ir content in the range examined (from zero to 5%), the catalytic activity increased and the CO selectivity decreased. Furthermore, the effect of support oxides was obtained: the catalytic activity was Ir/ZSM-5 ＞ Ir/SiO2 ＞ Ir/γ-Al2O3 and the CO selectivity was Ir/ZSM-5 ＜ Ir/γ-Al2O3 ＜ Ir/SiO2.