Effect of MOx (M = Ce, Ni, Co, Mg) on activity and hydrothermal stability of Pd supported on ZrO2-Al2O3 composite for methane lean combustion
Effect of MOx (M = Ce, Ni, Co, Mg) on activity and hydrothermal stability of Pd supported on ZrO2-Al2O3 composite for methane lean combustion
复制标题
MOx（M = Ce、Ni、Co、Mg）对 ZrO2-Al2O3 复合材料负载 Pd 贫甲烷燃烧活性和水热稳定性的影响
DOI：
10.1016/j.jtice.2018.01.038
复制
发表时间：
2018
影响因子：
5.7
通讯作者：
Chen Yaoqiang
中科院分区：
文献类型：
--
作者：
Wu Yang;Li Guangxia;Hu Wei;Huang Fujin;Chen Jianjun;Zhong Lin;Chen Yaoqiang
采用金属氧化物(Ce、Co、Ni、Mg氧化物)双溶剂法对Zr0.5Al0.5O1.75(ZA)进行改性。将Pd纳米颗粒负载在改性的ZA上，然后进行甲烷稀薄燃烧试验。系统地研究了样品的织构、结构和氧化还原性能、表面Pd的氧化态和稳定性。改性后的催化剂在750℃湿空气(10 体积%水蒸气)中老化10 h，即老化处理。结果表明，添加NiO、MgO或Co3O4后，Pd/ZA催化剂的活性和水热稳定性得到提高。特别是Pd/NiO/Zr0.5Al0.5O1.75(Pd/NiO/ZA)催化剂在水蒸气存在下的甲烷燃烧性能最好，与老化处理无关。X射线衍射图表明，Pd/NiO/ZA中存在尖晶石相。共吸附结果表明，Pd在新鲜和陈化Pd/NiO/ZA上的分散度最高。H_2程序升温还原(H_2-TPR)测试表明，Pd/NiO/ZA催化剂具有最好的还原性能。X射线光电子能谱(XPS)分析和程序升温氧化(TPO)实验表明，Pd/NiO/ZA催化剂具有最高的活性相PdO含量和稳定性。因此，Pd/NiO/ZA催化剂在稀燃天然气汽车尾气后处理中具有广阔的应用前景。
Zr0.5Al0.5O1.75(ZA) was modified by metal oxide (Ce, Co, Ni or Mg oxide)viadouble solvent method. The Pd nanoparticles were supported on the modified ZA and then tested for methane lean combustion. The textural, structural and redox properties, surface Pd oxidation states and stability of the samples were investigated systematically. The modified catalysts were aged in the 750 °C humid air (10 vol.% water vapor) for 10 h, namely aging treatment. It was found that the activity and hydrothermal stability of the Pd/ZA catalyst was enhanced after the addition of NiO, MgO or Co3O4. Particularly, the Pd/NiO/Zr0.5Al0.5O1.75(Pd/NiO/ZA) catalyst exhibited the best performance for methane combustion in the presence of water vapor, regardless of aging treatment. X-ray diffraction (XRD) patterns showed that the presence of spinel phase in the Pd/NiO/ZA. CO-chemisorption results demonstrated the highest Pd dispersion on the fresh and aged Pd/NiO/ZA. H2-temperature-programmed reduction (H2-TPR) measurements indicated that the Pd/NiO/ZA catalyst possessed the best reducibility regardless of aging treatment. X-ray photoelectron spectroscopy (XPS) analysis and temperature-programmed oxidation (TPO) experiments revealed that the Pd/NiO/ZA catalyst possessed the highest active phase PdO content and stability. Consequently, the Pd/NiO/ZA catalyst would be promisingly applied to exhaust after-treatment for lean-burn natural gas vehicles.