Cu-Ag/海泡石催化还原NO的研究

以天然海泡石为原料,对其进行酸改性并与活性氧化铝混合后作为催化剂载体,采用浸渍法制备了用于CO还原NO的Cu-Ag复合金属催化剂.对不同Ag负载量催化剂催化还原NO的活性进行了评价,考察了载体对催化剂催化活性的影响,用BET、XRD、SEM等对催化剂进行了表征.结果表明,当Ag负载量不超过5%时,复合金属催化剂性能好于单一金属催化剂;Ag负载量为2%时催化剂性能最好;采用海泡石-氧化铝混合物为载体的催化剂的孔径分布得到改善,对NO催化还原反应有更高的活性.

Study of Cu-Ag/sepiolite catalyst for NO reduction

The present paper is aimed to introduce the author's method of preparing a series of Cu-Ag catalysts for NO reduction by means of impregnation. The starting substance of the catalyst of NO_x reduction is actually a natural sepiolite, which was activated by acid-treatment and mixed with Al_2O_3 before being used as the supporting elements. To ensure the success of the experiments, the author has carefully calculated and evaluated the activities of NO reduction of the catalysts with different Ag contents with the supporting effect on the performance of catalysts fully considered. In addition, BET, XRD and SEM were used to define the characteristics of the catalysts concerned. Our experimental results demonstrate that Cu-Ag/Sep is much better than both Cu/Sep and Ag/Sep on the condition that Ag content is lower than 5%. However, the catalyst with 2% of Ag load has proved to produce the best activity. The main reason for their different activities seems due to the difference of the active Ag species among all the catalysts under consideration. When mixing with Al_2O_3, the pore size distribution of the support substance seems to be more suitable for the reaction, for the activity of Cu-Ag/Sep-Al_2O_3 is much more higher than Cu-Ag/Sep. The maximum conversion of NO on it can reach as high as 96%.