Monolithic Catalysts with Low Noble-Metal Content for Exhaust Purification of Small Gasoline Engines

A series of low noble-metal coment monolithic catalysts for exhaust purification of small gasoline engines was investigated, and it was found that the Pt/Rh-OSM/Al2O3 （where OSM was oxygen storage material） catalyst with Ce0.5Zr0.5-MnOx（3%MnOx） OSM held low light-off temperature for CO, HC, and NO; quite wide three-way window, and outstanding thermal stability. The catalyst could efficiently comrol exhaust emission of small gasoline engines.     

耐高温高比表面积载体对密偶催化剂性能的影响

制备了耐高温高比表面积氧化铝载体La-Al2O3,用于制备汽车尾气净化密偶催化剂,并与La-Ba/Al2O3和商业γ-Al2O3比较.结果表明,La-Al2O3具有较大的比表面积和较好的耐高温性能以及较好的孔结构,其制备的催化剂比La-Ba/Al2O3和商业γ-Al2O3制备的催化剂具有良好的催化活性和抗老化性能.     

铑在不同载体材料上的分配比对低含量贵金属催化剂性能的影响

采用浸渍法制备了一系列低Pt、Rh含量的Pt-Rh型汽车尾气净化催化剂.研究了在Pt、Rh含量一定以及其他条件不变的情况下,只改变铑在不同栽体上的分配比对催化剂性能的影响,测定了催化剂对C3H8、CO、NO的起燃温度,并对催化剂样品进行了程序升温还原(H2-TPR)、程序升温脱附(O2-TPD)表征.结果表明:新鲜催化剂对C3H8、CO、NO的起燃温度相差不大,但经过1000℃、5h的水热老化后,催化剂性能发生了显著的变化,C3H8、CO、NO的起燃温度出现较大的差异,说明了铑在不同栽体上的分配比对催化剂性能有一定影响,特别是对催化剂的抗老化性能影响较大.     

Influence of Ce0.35Zr0.55Y0.10 Solid Solution on Performance of Pt-Rh Three-Way Catalysts

Ce0.35Zr0.55Y0. 10 solid solution was prepared by co-precipitation technique and characterized by specific surface area measurements （BET） and X-ray diffraction （XRD）. Ce0.35Zr0.55Y0.10 was used to prepare low Pt-Rh threeway catalyst （TWC）, and its influence on the performance of TWC was investigated. The results revealed that Ce0.35 Zr0.55Y0.10 had a cubic structure similar to Ce0.50Zr0.50O2 and its specific surface area can maintain higher than Ce0.50 Zr0.50O2 after 1000 ℃ calcination for 5 h. Being hydrothermal aged at 1000 ℃ for 5 h, the catalyst containing Ce0.35 Zr0.55Y0.10 still exhibited higher conversion of C3H8, CO and NO and lower light-off temperature in comparison with Ce0.50Zr0.50O2 TWC.     

Catalytic Partial Oxidation of Methane over Ni/CeO2-ZrO2-Al2O3

Nickel catalysts supported on CeO2-ZrO2-CeO2,ZrO2-Al2O3 and Al2O3 were prepared and characterized by means of X-ray diffraction（XRD）,BET areas,H2 temperature-programmed reduction（H2-TPR）,and X-ray photoelectron spectroscopy（XPS）.Through the test of catalytic partial oxidation of methane（CPOM）,Ni/CeO2-ZrO2-Al2O3 displayed the highest activity,which resulted from its largest BET area and best NiO dispersion.Furthermore,Ni/CeO2-ZrO2-Al2O3 maintained a long-time stability in CPOM,which was attributed to its best coking resistance among all the prepared catalysts.     

烟气脱硫用炭材料的改性研究进展

介绍了活性炭的物理结构、化学性质及其脱硫机理,并从材料角度分析了提高活性炭脱硫性能的方法,综述了烟气脱硫用炭材料的表面结构改性和表面化学改性。与商品活性炭相比,经过改性处理的活性炭的脱硫性能明显提高,具有良好的工业应用前景。     

甲烷在整体式Co基催化剂上的燃烧性能

以Ce0.25Zr0.50Mn0.25O2(OSM)和YSZ—Al2O3(Y2O3，ZrO2稳定的γ—Al2O3)为载体，制备了Co／OSM和Co／YSZ—Al2O3整体式催化剂，以及不同Co／OSM：Co／YSZ—Al2O3比例的Co／OSM Co／YSZ-Al2O3整体式催化剂．研究了上述催化剂的甲烷催化燃烧性能，并利用XRD和H2-TPR对催化剂进行了表征．XRD结果表明，在OSM和YSZ-Al2O3上Co均以高分散形式存在．H2-TPR结果表明，Co／OSM Co／YSZ-Al2O3样品的可还原性随着Co／OSM含量的增加而提高，表现出可调节的还原性能．Co／OSM的甲烷燃烧催化活性高于Co／YSZ—Al2O3，Co／OSM Co／YSZ—Al2O3表现出协同作用和高活性．     

低温Ni/AC脱硫剂的制备与表征

采用过量浸渍法制备了Ni/AC脱硫剂,着重考察了酸预处理和操作条件对Ni/AC脱硫性能的影响,同时用BET、XPS和XRD对脱硫剂的织构和结构性能进行了表征.结果表明:酸预处理能增加活性炭载体的比表面积和孔容,提高表面含氧官能团的比例;酸预处理能显著提高Ni/AC的脱硫活性,表现出高的低温脱硫活性;操作条件对Ni/AC的脱硫活性具有较大的影响,脱硫反应必须在适宜反应条件下进行,Ni/AC脱硫剂才能表现出好的脱硫活性.     

Pt/MoO3/ZrO2催化剂的制备及三效催化性能的研

采用浸渍法制备了MoO₃/ZrO₂, 用低温氮吸附-脱附法和NH3-程序升温脱附法(TPD)分别对其比表面积和酸碱性进行了表征. 结果表明, MoO₃/ZrO₂具有106.8m²/g的比表面积和超强酸的性能. 用等体积浸渍法制备了Pt/MoO₃/ZrO₂催化剂, 在汽车尾气模拟气中考察了其对C₃H₈、CO和NO的催化活性.与传统三效催化剂Pt/La₂O₃/Al₂O₃相比较, Pt/MoO₃/ZrO₂具有更好的低温起燃性能和更宽的空燃比窗口, 并显著地改善了C₃H₈在富氧状态下的转化效率. 通过XRD、H₂-TPR对催化剂进行了表征, 结果表明, Pt在催化剂载体上具有高度的分散性和优异的氧化还原性能.