The Pd and K co-supported Mg-Al hydrotalcite oxides(Pd-K/MgAlO)were prepared by impregnation method. The activities of the catalyst were investigated for simultaneous catalytic removal of diesel soot and NOχ. For comparison, Pd/MgAlO and K/MgAlO were also studied. The loading of Pd is not effective for catalytic soot combustion but can improve the selectivity for CO2. With the introduction of NOχ, however, Pd/MgAlO shows a small increase in activity by promoting the oxidation of NO to NO2. Simultaneously, a limited amount of NOχ is removed. When Pd and K coexist, the temperatures of soot combustion are significantly decreased. Furthermore, the ignition temperature can be further lowered to 240 °C by the introduction of NOχ. The effect of contact types between the catalyst and the soot is decreased. The activity of Pd-K/MgAlO for soot combustion is attributed to K rather than to Pd. Due to the existence of the synergism between Pd and K, the maximum conversion of NOχ reaches 45%, higher than that of Pd/MgAlO or K/MgAlO. The high conversion of NOχ during soot combustion in NOχ and O2 atmosphere is ascribed not only to the reduction of NOχ with soot but also to the decomposition of NOχ.%采用浸渍法将Pd和K共同负载到Mg-Al水滑石基氧化物(Pd-K/MgAlO)上,用于碳烟颗粒和NOx的同时去除,并与Pd/MgAlO和K/MgAlO催化剂进行了比较.研究发现,单独的Pd负载不具备催化碳烟燃烧的活性,但可以提高生成CO2的选择性；引入NOx后,Pd可以通过促进NO氧化对碳烟燃烧有所改善,同时可以去除少量的NOx.当Pd与K共负载时,碳烟燃烧温度显著降低；引入NOx后,起燃温度进一步降低至240℃左右,而且碳烟燃烧受接触方式的影响不大,其中催化作用的主要影响组分是K.在Pd和K协同作用下,NOx的最大去除效率达到45％,高于Pd/MgAlO和K/MgAlO的去除效率.其中,一部分NOx被碳烟还原,另一部分则发生了分解反应.
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