新型汽车尾气净化器载体材料性能及净化效果研究

Preparation and purifying efficiency of a new silicon carbide porous ceramics in auto exhaust purification

用三维贯通网络结构的SiC多孔陶瓷作为汽车尾气净化CO和CH的载体材料,研究了SiC多孔陶瓷的性能和气体净化效果。结果表明:(1)SiC多孔陶瓷主孔道呈三维贯通网络结构,主孔道孔径为300～400μm;具有优异的抗热震性和电致发热性能,是净化汽车尾气催化剂载体的理想材料。(2)SiC多孔陶瓷加热迅速、表面温度高,可以显著提高净化器内的气体温度;在不用涂覆催化剂的情况下,利用SiC多孔陶瓷的电致发热性能就可以有效地实现CO和CH的转化,对汽车尾气模拟气体具有良好的净化效果。

Silicon carbide porous ceramics with 3-D solid net framework structure were prepared and used as catalyst carrier for purifying CH and CO pollutants in auto exhaust. Microporous with the diameter of 300-400 μm were observed in the SiC porous ceramics. The SiC porous ceramics presented excellent thermal shock resistance so was suitable for use as ideal catalyst carrier materials. The heating capability of SiC porous ceramics was tested, when electrified under the voltage of 15 V and 20 V for 200 s,the SiC porous ceramics temperature could reach to 771 ℃ and 933 ℃. The high purifying effectively of SiC porous ceramics was achieved under the voltage of 20 V without coating catalyst,the mixture conversion rate of CO and CH could reach 80% and 90% ,respectively.