Chen Yaoqiang

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

Abstract 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.

Effect of Metal Oxide Doping into Ce0.5Zr0.5O2 on Catalytic Activity of MnOx/γ-Al2O3/Ce0.45Zr0.45M0.1Ox (M = Y, La, Mn) Honeycomb Catalysts

Abstract This article showed that the catalytic activity of MnO x /γ-Al 2 O 3 /Ce 0.5 Zr 0.5 O 2 monolithic catalyst toward the catalytic combustion of ethanol in a fixed bed reactor could be greatly improved by doping three metal oxides into Ce 0.5 Zr 0.5 O 2 . The catalytic activity of MnO x /γ-Al 2 O 3 /Ce 0.45 Zr 0.45 M 0.1 O x (M = Y, La, Mn) is better than that of Mn O x /γ-Al 2 O 2 /Ce 0.5 Zr 0.5 O 2 . The order of activity of the catalysts is as follows: MnO x /γ-Al 2 O 3 /Ce 0.45 Zr 0.45 Y 0.1 O x > MnO x /γ-Al 2 O 3 /Ce 0.45 Zr 0.45 La 0.1 O x > MnO x /γ-Al 2 O 3 /Ce 0.45 Zr 0.45 Mn 0.1 O x > MnO x /γ-Al 2 O 3 /Ce 0.5 Zr 0.5 O 2 . The influence of the loading amount of manganese oxide in enhancing the catalytic activity of MnO x /γ-Al 2 O 3 /Ce 0.45 Y 0.1 O x was investigated. The results showed that when MnO 2 loading amount was 10% (mass fraction), the MnO x /Al 2 O 3 /Ce 0.45 Zr 0.45 Y 0.1 O x catalyst recorded the highest activity.

Effect of Fe2 O3 Loading Amount on Catalytic Properties of Monolithic Fe2O3 /Ce0.67Zr0.33O2 -Al2O3 Catalyst for Methane Combustion

Abstract Ce 0.67 Zr 0.33 O 2 -Al 2 O 3 solid solution was prepared by the co-precipitation method. Fe 2 O 3 -based catalysts supported on the solid solution were obtained by the impregnation method. The article revealed that the optimal loading amount of Fe 2 O 3 on Ce 0.67 Zr 0.33 O 2 -Al 2 O 3 in our experimental condition for catalytic combustion of methane was 8% (mass fraction). The prepared catalysts were characterized by BET, TPR, XRD analyses, and their catalytic activity was investigated after being calcined at 873 K and after being aged in water gas at 1273 K. When the loading amount of Fe 2 O 3 was 8% (mass fraction), the catalyst held the highest activity, and the best temperature speciality and thermal stability. The complete-conversion temperature of methane for fresh and aged sample was 788 and 838 K, respectively. The range between the light-off temperature and the complete-conversion temperature was only 15 K. The characterization results of XRD indicated that Fe 2 O 3 was well dispersed on the Ce 0.67 Zr 0.33 O 2 -Al 2 O 3 matrix. The results of BET and TPR were in good harmony with the catalytic activity results.

Catalytic Activity of C 3 H 8 over Fresh and Aged Pd/Al 2 O 3 Close-Coupled Catalysts

Abstract The Pd/Al 2 O 3 close-coupled catalysts supported on modified alumina were prepared by an impregnation method, and then characterized by H 2 -temperature programmed reduction (H 2 -TPR), CO chemisorption, and X-ray photoelectron spectroscopy (XPS). Both total catalytic activity and single reactions in related to C 3 H 8 conversion were tested in simulated exhaust gas. The results show that the amount of active PdO x decreases and negative metallic Pd 0 appears during aging treatment. The light-off temperature ( T 50 ) and complete conversion temperature ( T 90 ) increase by 76 °C and 64 °C, respectively. After aging treatment, signifying that the low-temperature activity decreases more obviously than high temperature property. The results of comparison among single reactions indicate that the light-off activity of reactions which occur in atmosphere with the participation of NO but without H 2 O injection decreases dramatically after the aging treatment. The inhibitive effect of NO on light-off activity and the positive effect of H 2 O on high temperature property become obvious during the aging treatment.

陈化体系中醇对Ce 0.65 Zr 0.35 O 2 及其负载的单Pd催化剂性能的影响

采用共沉淀法制备了Ce 0.65 Zr 0.35 O 2 (CZ)储氧材料, 分别以乙醇-水、丙醇-水、乙二醇-水、丙三醇-水体系对沉淀物进行陈化, 研究了醇的种类对CZ及其负载的单Pd催化剂性能的影响。对CZ进行了扫描电镜(SEM), N 2 -吸脱附分析, 对Pd/CZ进行了粉末X射线衍射(XRD)、X射线光电子能谱(XPS)、储氧量 (OSC)和程序升温还原( H 2 -TPR)的表征, 并考察了三效催化性能。结果表明, 醇的种类对CZ及Pd/CZ的性能有显著影响。在乙醇–水和丙醇–水陈化体系中制备的CZ分散性高, 颗粒堆积松散, 比表面积和孔径大, 孔容高, 且具有优异的热稳定性, 其中丙醇–水陈化体系中制备的CZ老化后比表面积和孔容分别可达28 m 2 /g和0.1 mL/g, 具有最高的热稳定性, 其负载的单Pd催化剂在老化后对C 3 H 8 、CO和NO转化显著优于乙二醇–水和丙三醇–水陈化体系中制备的CZ所制备的催化剂。采用共沉淀法制备了Ce 0.65 Zr 0.35 O 2 (CZ)储氧材料, 分别以乙醇-水、丙醇-水、乙二醇-水、丙三醇-水体系对沉淀物进行陈化, 研究了醇的种类对CZ及其负载的单Pd催化剂性能的影响。对CZ进行了扫描电镜(SEM), N 2 -吸脱附分析, 对Pd/CZ进行了粉末X射线衍射(XRD)、X射线光电子能谱(XPS)、储氧量 (OSC)和程序升温还原( H 2 -TPR)的表征, 并考察了三效催化性能。结果表明, 醇的种类对CZ及Pd/CZ的性能有显著影响。在乙醇–水和丙醇–水陈化体系中制备的CZ分散性高, 颗粒堆积松散, 比表面积和孔径大, 孔容高, 且具有优异的热稳定性, 其中丙醇–水陈化体系中制备的CZ老化后比表面积和孔容分别可达28 m 2 /g和0.1 mL/g, 具有最高的热稳定性, 其负载的单Pd催化剂在老化后对C 3 H 8 、CO和NO转化显著优于乙二醇–水和丙三醇–水陈化体系中制备的CZ所制备的催化剂。

Influence of Alcohol on Performance of Ce

采用共沉淀法制备了Ce 0.65 Zr 0.35 O 2 (CZ)储氧材料, 分别以乙醇-水、丙醇-水、乙二醇-水、丙三醇-水体系对沉淀物进行陈化, 研究了醇的种类对CZ及其负载的单Pd催化剂性能的影响。对CZ进行了扫描电镜(SEM), N 2 -吸脱附分析, 对Pd/CZ进行了粉末X射线衍射(XRD)、X射线光电子能谱(XPS)、储氧量 (OSC)和程序升温还原( H 2 -TPR)的表征, 并考察了三效催化性能。结果表明, 醇的种类对CZ及Pd/CZ的性能有显著影响。在乙醇–水和丙醇–水陈化体系中制备的CZ分散性高, 颗粒堆积松散, 比表面积和孔径大, 孔容高, 且具有优异的热稳定性, 其中丙醇–水陈化体系中制备的CZ老化后比表面积和孔容分别可达28 m 2 /g和0.1 mL/g, 具有最高的热稳定性, 其负载的单Pd催化剂在老化后对C 3 H 8 、CO和NO转化显著优于乙二醇–水和丙三醇–水陈化体系中制备的CZ所制备的催化剂。采用共沉淀法制备了Ce 0.65 Zr 0.35 O 2 (CZ)储氧材料, 分别以乙醇-水、丙醇-水、乙二醇-水、丙三醇-水体系对沉淀物进行陈化, 研究了醇的种类对CZ及其负载的单Pd催化剂性能的影响。对CZ进行了扫描电镜(SEM), N 2 -吸脱附分析, 对Pd/CZ进行了粉末X射线衍射(XRD)、X射线光电子能谱(XPS)、储氧量 (OSC)和程序升温还原( H 2 -TPR)的表征, 并考察了三效催化性能。结果表明, 醇的种类对CZ及Pd/CZ的性能有显著影响。在乙醇–水和丙醇–水陈化体系中制备的CZ分散性高, 颗粒堆积松散, 比表面积和孔径大, 孔容高, 且具有优异的热稳定性, 其中丙醇–水陈化体系中制备的CZ老化后比表面积和孔容分别可达28 m 2 /g和0.1 mL/g, 具有最高的热稳定性, 其负载的单Pd催化剂在老化后对C 3 H 8 、CO和NO转化显著优于乙二醇–水和丙三醇–水陈化体系中制备的CZ所制备的催化剂。

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Zr0.5Ti0.5O2was prepared by co-precipitation and tested for its catalytic performance under supercritical conditions when mixed with a CeO2-Al2O3(CA) base catalyst.The catalysts were characterized with an automatic adsorption instrument(BET method),X-ray diffraction(XRD),transmission electron microscopy(TEM),and temperature programmed desorption(TPD).It was found that Zr0.5Ti0.5O2significantly lowered the temperature of the cracking reaction,and increased the thermal cracking gas rate by a factor of2.8 times as large as that at 600 °C for the CA base catalyst.The gas rate was increased by a factor of 4.0 times when it was doped into the CA base catalyst,and the heat sink increased by 0.55 MJ kg 1over that of thermal cracking at 650 °C.BET results show that the Zr0.5Ti0.5O2-doped CA base catalyst has a double-pore structure that enhances ethylene selectivity.NH3-TPD result indicates that the acidity of the catalyst increased by 4.0times,indicating improved surface acidity conducive to alkene generation.采用共沉淀法制备了Zr0．5Ti0.5O2载体材料，将其掺杂在CeO2-Al2O3（CA）基催化剂中，并对其催化活性进行了超临界裂解测试，采用全自动吸附仪、X射线衍射（XRD）、透射电镜（TEM）、程序升温脱附（TPD）等方法对催化剂进行了表征．实验结果表明，催化剂能够明显降低裂解反应的温度，600℃CA基催化剂产气率是热裂解的2．8倍，掺杂Zr0．5Ti0.5O2 载体材料的CA基催化剂是热裂解的4．0倍，650℃时，掺杂Zr0.5Ti0.5O2载体材料的CA基催化剂热沉提高了0．55MJ·kg-1．BET结果表明，掺杂Zr0.5Ti0.5O2载体后催化剂出现双孔结构，部分小孔的出现使得乙烯的选择性提高；NH3-TPD结果表明，掺杂Zr0.5Ti0.5O2载体材料后，催化剂强酸位的酸量增加了4．0倍，催化剂表现出更强的表面酸性和更集中的强酸酸中心密度，有利于裂解多产烯烃．