柴油机尾气净化用的钙钛矿型催化剂的研究

STUDY ON CATALYSTS OF PEROVSKITE TYPE USED IN DIESEL ENGINE TAIL GAS PURIFICATION

用浸渍法制备了多种ABO_3型催化剂,考察了多种因素对其活性的影响及作用机制。柴油机台架实验结果表明,在A位掺杂Sr可提高催化剂的活性;稀土在最后一次浸渍液中浸渍,以二次浸渍为宜;堇青石陶瓷蜂窝状催化剂的性能优于γ-Al_2O_3球状催化剂。蜂窝状催化剂上CO的起燃温度T_(50)％=110℃,而T_(90)％=157℃;在温度仅为200℃,而空速高达70000h^(-1)的条件下CO的净化率仍达90％;积碳起燃温度为323℃,优于Pt族贵金属催化剂;热稳定性和对CO浓度的适应性较好,且具有抗SO_2中毒能力。

Many kinds of ABO_3 catalysts were made by dipping method, influences by many factors on its activity and action mechanism were investigated. Experimental results on diesel engine platform showed that mixxing Sr in A site can improve activity of catalyst, rare-earth dipping in the fast dipping liquid is better than two times dipping, characteristics of cordierite honeycomb ceramics is better than γ-Al_2O_3 spheroid catalyst. The temperature of CO ignition T_(50)％ on honeycomb catalyst is 110℃, and T_(90)％ is 157℃. Under the condition of 200℃ and 70000h^(-1) space vilocity, CO purification efficiency is 90％. An ignition temperature of carbon concentration is 323℃. It is better than catalysts of Pt family metal. Characteristics of heat atibility and adaptability to CO consistency are better, and it can resist SO_2