Zr_0.5Al_0.5O_1.75 (ZA) was modified by metal oxide (Ce, Co, Ni or Mg oxide) via double 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/Zr_0.5Al_0.5O_1.75 (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.

Zr _0.5 Al _0.5 O _1.75（ZA）通过金属氧化物（Ce，Co，Ni或Mg氧化物）通过双溶剂法改性。将Pd纳米颗粒负载在改性ZA上，然后进行贫甲烷燃烧测试。系统地研究了样品的结构，结构和氧化还原性能，表面Pd氧化态以及稳定性。改性催化剂在750°C的潮湿空气（10％体积的水蒸气）中老化10小时，即老化。发现在添加NiO，MgO或Co ₃ O ₄后，Pd / ZA催化剂的活性和水热稳定性得到了提高。特别地，Pd / NiO / Zr _0.5 Al _0.5 O无论老化处理如何，_1.75（Pd / NiO / ZA）催化剂在存在水蒸气的情况下均表现出甲烷燃烧的最佳性能。X射线衍射（XRD）图谱表明在Pd / NiO / ZA中存在尖晶石相。CO化学吸附结果表明，在新鲜和老化的Pd / NiO / ZA上Pd的分散度最高。H _2-程序升温还原（H ₂-TPR）测量表明，无论老化处理如何，Pd / NiO / ZA催化剂都具有最佳的还原性。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催化剂有望用于稀燃天然气汽车的排气后处理。