柴油机由于其较强的动力性与耐久性等优势,已经广泛应用于运输、农业、建筑等重工业领域.然而,柴油机排放的尾气污染物,如炭烟颗粒和氮氧化物(N O x),严重危害人们的健康和生活环境.因此,消除柴油机尾气中的炭烟颗粒和氮氧化物已成为一项重要的研究课题.通过控制原料中CuSO4的添加量,采用一锅法合成了含有不同Cu含量的Cu(X)/SSZ-13分子筛催化剂.通过 XRD、N2吸附-脱附、SEM、H2-TPR、NO-TPO、NH3-TPD、Soot-TPR 等表征手段,研究了制备的Cu(X)/SSZ-13分子筛催化剂的形貌和物理化学性质,并测试了所合成的催化剂在同时消除炭烟和NOx方面的活性.结果表明,不同Cu含量的Cu(X)/SSZ-13分子筛在同时消除炭烟和NOx方面的活性存在明显差异,Cu含量还会影响Cu(X)/SSZ-13分子筛的形貌、比表面积和氧化还原性能.当Cu含量为1.25时,制备的Cu(1.25)/SSZ-13催化剂表现出最佳的催化性能,其在153～427 ℃温度范围的NO转化率超过90％,炭烟燃烧的峰值温度(Tm)为504 ℃.
Abstract
Diesel engines have been widely applied in heavy industries such as transportation,agricul-ture,and construction due to their advantages of strong power and durability.However,the pollutants emitted by diesel engines,including soot particles and nitrogen oxides(NOx),severely threaten peo-ple's health and environment.Therefore,the elimination of soot particles and NOx from diesel engine exhausts has become an important research topic.In this paper,Cu(X)/SSZ-13 zeolite catalysts with different Cu proportions(Cu(X)/SSZ-13)were synthesized by one-pot method by controlling the amount of CuSO4 added to the raw materials.The morphology and physicochemical properties of the prepared Cu(X)/SSZ-13 zeolite catalysts were studied using XRD,N2 adsorption-desorption,SEM,H2-TPR,NO-TPO,NH3-TPD,Soot-TPR and other characterization methods.The activities of as-prepared catalysts for simultaneous elimination of soot and NOx were tested.The results indicated that Cu(X)/SSZ-13 zeolite catalysts with different Cu contents exhibited significantly different activities in the simultaneous elimination of soot and NOx.Additionally,the Cu content could also cause changes in the morphology,specific surface area,and redox performance of Cu(X)/SSZ-13 zeolite catalysts.When the Cu proportion was 1.25,the prepared Cu(1.25)/SSZ-13 zeolite catalyst exhibited the best catalytic performance,with the temperature window of 153-427 ℃ for NO conversion greater than 90％,and the peak temperature of soot combustion(Tm)is 504 ℃.
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