贵金属催化同时去除碳颗粒和NOx

Simultaneous removal of soot and NOx with noble metal catalysts

摘要:

为系统研究贵金属催化同时去除碳颗粒和NO_x的活性及抗硫抗水性能,采用等体积浸渍法制备了一系列贵金属催化剂(Ru／ZrO₂、Ag／ZrO₂、Rh／ZrO₂、Pd／ZrO₂、 Pt／ZrO₂ 、Ir／ZrO₂、 Au／ZrO₂),研究了富氧条件下其催化去除碳颗粒和NO_x的活性,并考察了SO₂和H₂O对其催化活性的影响．结果表明:在富氧条件下,贵金属的负载提高了碳颗粒和NO_x同时去除的活性,其中Ru／ZrO₂、Ag／ZrO₂和Pd／ZrO₂的催化活性较佳;SO₂和H₂O对Ir／ZrO₂催化同时去除碳颗粒和NO_x、Pt／ZrO₂催化去除碳颗粒、Ru／ZrO₂催化去除NO_x有促进作用,但对其他贵金属有抑制作用．

Abstract:

In order to systematically evaluate the activities of the noble metal catalysts for simultaneous removal of soot and NO_x and the corresponding effect of sulfur and water, a series of noble metal catalysts (Ru／ZrO₂, Ag／ZrO₂, Rh／ZrO₂, Pd／ZrO₂, Pt／ZrO₂, Ir／ZrO₂, Au／ZrO₂) were prepared by iso-volumetric impregnation method firstly. Then the activities of the noble metal catalysts for simultaneous removal of soot and NO_x were measured under oxygen-rich condition, and the effect of SO₂ and H₂O on the performances of those catalysts were also studied. Experimental results showed that noble metal can improve the activities of simultaneous removal of soot and NO_x significantly. Compared with the other catalysts, Ru／ZrO₂, Ag／ZrO_2and Pd／ZrO₂ have higher catalytic activity. The existence of SO₂ and H₂O promoted Ir／ZrO₂ catalystal removal of soot and NO_x simultaneously, promoted Pt／ZrO₂ catalyze for soot oxidation, Ru／ZrO₂ for NO_x reduction and inhibited the catalytic activities of other noble metals.