Synthesis and catalytic properties of Ce0.6Zr0.4O2 solid solutions in the oxidation of soluble organic fraction from diesel engines
Synthesis and catalytic properties of Ce0.6Zr0.4O2 solid solutions in the oxidation of soluble organic fraction from diesel engines
复制标题
Ce0.6Zr0.4O2固溶体的合成及其在柴油机可溶性有机馏分氧化中的催化性能
DOI：
10.1016/j.apcatb.2007.06.011
复制
发表时间：
2007-11
影响因子：
22.1
通讯作者：
Zhang, Yexin
中科院分区：
文献类型：
--
作者：
Yu, Pengfei;Wang, Shilong;Mu, Zonggang;Zhang, Zhaoliang;Ni, Xianzhi;Zheng, Lisheng;Zhang, Yexin
分别采用共沉淀法、类溶胶-凝胶法、溶液燃烧法和表面活性剂辅助法合成了Ce0.6Zr0.4O2固溶体。采用TG-DTA法研究了Ce0.6Zr0.4O2固溶体和γ-Al 2 O3固溶体对柴油机可溶性有机物（SOF）氧化的催化性能。采用XRD、BET比表面积和孔分布、SEM、TEM、粒度分布等测试手段对其物化性能进行了表征。XRD和TEM结果表明，所制备的样品在900°C空气中热处理2 h后形成了Ce0.6Zr0.4O2固溶体。通过控制制备条件，共沉淀法制备的Ce0.6Zr0.4O2比表面积高达153.71m2/g。值得注意的是，在350°C下点燃的新鲜Ce0.6Zr0.4O2在空气中900°C热处理2 h后，比表面积和颗粒尺寸几乎没有下降。此外，其体积密度最低。用一汽大众的SJ 5 W/40柴油机油替代国产宝来1.9TDI柴油汽车的SOF机油。通过DTA曲线的归一化峰面积和外推起始温度评价催化活性。采用直接非线性回归模型，编制了计算机程序，模拟TG/DTG曲线，确定热过程和动力学参数。发现在氮气气氛下观察到润滑油蒸发/分解和热分解（热解）。Ce0.6Zr0.4O2和γ-Al 2 O3对润滑油蒸发组分有抑制作用。而在空气气氛下，即在润滑油氧化（燃烧）过程中，蒸发/分解，低温氧化和高温氧化区分。Ce0.6Zr0.4O2固溶体是润滑油氧化的活性催化剂，其中溶液燃烧法制备的样品活性最高，这主要是由于烧结后样品的比表面积和粒径保持不变，且体积密度最低。而γ-Al 2 O3更像是一种载体。Ce0.6Zr0.4O2与γ-Al 2 O3之间存在协同作用：γ-Al 2 O3吸附润滑油，将润滑油保留在其孔结构中，而Ce0.6Zr0.4O2固溶体在起燃温度达到100 ℃时开始氧化反应。低温固溶燃烧法制备的CeO 2-ZrO 2固溶体在柴油机氧化催化剂中具有良好的应用前景。
Ce0.6Zr0.4O2solid solutions were synthesized by co-precipitation, sol–gel like method, solution combustion and surfactant-assistant approaches, respectively. The catalytic properties of bulk and γ-Al2O3supported Ce0.6Zr0.4O2solid solutions were studied for the oxidation of soluble organic fractions (SOF) from diesel engines by TG-DTA method. The physicochemical properties were characterized by XRD, BET surface area and pore distribution, SEM, TEM, and particle size distribution techniques. XRD and TEM results show that a Ce0.6Zr0.4O2solid solution was formed for samples as-prepared and heat-treated at 900°C for 2h in air. The co-precipitation derived Ce0.6Zr0.4O2has as high BET surface area as 153.71m2/g by controlling preparation conditions. Notable is that the surface area and particle size for fresh Ce0.6Zr0.4O2ignited at 350°C decreased little after a thermal treatment in air at 900°C for 2h. Furthermore, its bulk density is lowest. The commercial engine oil (SJ5W/40) for FAW-VOLKSWAGEN, which was used by Bora 1.9 TDI diesel cars in China market was substituted for SOF. The catalytic activity was evaluated by normalized peak areas and extrapolated onset temperatures of DTA curves. A computer program was developed by direct non-linear regression model for simulation of TG/DTG curves to determine the thermal processes and kinetic parameters. It is found that lube evaporation/decomposition and thermal decomposition (pyrolysis) were observed under a nitrogen atmosphere. Lube evaporation fractions were inhibited by Ce0.6Zr0.4O2and γ-Al2O3. While under an air atmosphere, namely, in the process of lube oxidation (combustion), evaporation/decomposition, low-temperature oxidation and high-temperature oxidation were distinguished. Ce0.6Zr0.4O2solid solutions are active catalysts for lube oxidation, in which the sample prepared by solution combustion has the highest activity, mainly due to the maintenance of the surface area and particle size upon sintering and its lowest bulk density. However, γ-Al2O3is more like a support. There exists synergism between Ce0.6Zr0.4O2and γ-Al2O3: γ-Al2O3adsorbs lube retaining it within its pore structure, whereas, Ce0.6Zr0.4O2solid solutions initiate oxidation reactions when light-off temperatures reach. The application of CeO2-ZrO2solid solution prepared by solution combustion at lower temperature would be promising in diesel oxidation catalysts.
登录
查看更多内容
影响因子：
10.9
作者：
S. Collura;N. Chaoui;A. Koch;J. Weber
通讯作者：
S. Collura;N. Chaoui;A. Koch;J. Weber
影响因子：
7.5
作者：
D. Çelebioğlu;S. Baǧci
通讯作者：
D. Çelebioğlu;S. Baǧci
影响因子：
22.1
作者：
Hori, CE;Permana, H;Belton, D
通讯作者：
Belton, D
DOI：
10.1016/s0965-9773(98)00131-7
发表时间：
1998-08
期刊：
Nanostructured Materials
影响因子：
--
作者：
S. Aruna;K. C. Patil
通讯作者：
S. Aruna;K. C. Patil
影响因子：
4.4
作者：
G. Stratakis;A. Stamatelos
通讯作者：
G. Stratakis;A. Stamatelos