Au nanoparticles were assembled on palygorskite (PAL) to form Au/PAL nanocomposites via a deposition–precipitation method. Samples were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and gas chromatography (GC). Results indicated that Au nanoparticles, with a particle size of 2–7 nm, were uniformly immobilized on the surface of PAL with the coexistence of Au and Au₂O₃. Ortho-dichlorobenzene (o-DCB) was first fixed on Au₂O₃ then completely oxidized to CO₂, H₂O, HCl by metallic Au. The reaction rate of o-DCB was approximately second order with calculated activation energy of −3.4 kJ/mol, while the reaction order of O₂ was zero order under sufficient oxygen. The catalytic activity could reach 99% at a Au/(Au + Au₂O₃) molar ratio of 0.83, three times of that without PAL support. Mechanism for enhanced catalytic activity under Au–Au₂O₃ coexistence system was discussed.

中文翻译：

---

在坡缕石上组装的Au纳米颗粒：增强的催化性能和Au–Au ₂ O ₃共存

通过沉积-沉淀法将金纳米颗粒组装在坡缕石（PAL）上形成Au / PAL纳米复合材料。使用X射线衍射（XRD），傅里叶变换红外光谱（FTIR），X射线光电子光谱（XPS），透射电子显微镜（TEM）和气相色谱（GC）对样品进行表征。结果表明，Au和Au ₂ O ₃共存，粒径为2–7 nm的Au纳米颗粒均匀地固定在PAL的表面上。首先将邻二氯苯（o -DCB）固定在Au ₂ O _3上，然后通过金属Au将其完全氧化为CO ₂，H ₂ O和HCl。反应速度o -DCB约为二阶，计算出的活化能为-3.4 kJ / mol，而在充足的氧气下O ₂的反应阶为零阶。Au /（Au + Au ₂ O ₃）摩尔比为0.83时，催化活性可以达到99％，是没有PAL载体的三倍。讨论了在Au–Au ₂ O ₃共存体系下增强催化活性的机理。