Pd/Mn/Ba/Al催化剂的NO_x存储-还原性能研究

A Study on Storage-reduction of NO_x Over Pd/Mn/Ba/Al Catalyst

采用分步等体积浸渍法制备了Pd/Mn/Ba/Al系列催化剂,并用DR IFTS、TPD、TPSR等方法进行了表征,考察了催化剂在不同温度点NOx的存储量以及存储-还原循环中NOx的脱除率.结果表明,NO更容易在MNOx上形成亚硝酸盐,Mn的加入显著提高了Pd/Ba/Al的低温存储活性,与Pd/Ba/Al相比,Pd/Mn/Ba/Al在30℃、100℃、200℃、300℃的存储量分别提高了87%、59%、32%、91%,循环实验表明,在200℃和300℃时,NOx的脱除率分别提高了5%和37%,而在400℃的NOx脱除率稍有降低.

The performance of NOx storage capacity（NSC） and the activity of storage-reduction over Pd/Ba/Al2O3 and Pd/Mn/Ba/Al2O3 catalyst were investigated at different temperatures.The Pd catalysts were prepared by inci-pient impregnation and characterized by TPD、 TPSR and DRIFTS.The results indicated that the addition of Mn can promote the NOx storage performance of the Pd/Ba/Al catalyst at low temperatures due to the easier adsorption of NO in the form of nitrite on Mn.Therefore,the NSC increased 87% at 30 ℃、 59% at 100 ℃、 32% at 200 ℃ and 91% at 300 ℃,respectively.The results of storage-reduction cyclings showed that the NOx conversion of Pd/Mn/Ba/Al increased 5% at 200 ℃ and 37% at 300 ℃,while slightly decreased at 400 ℃.