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采用具有分等级孔道结构的SiO2(HMS)为载体,通过润湿浸渍引入少量CeO2,经焙烧得到CeO2/HMS复合载体,然后采用沉积沉淀法负载上Au纳米粒子,得到Au/CeO2/HMS三元复合催化剂.通过X射线衍射、程序升温还原和原位红外光谱等手段表征了催化剂的结构.结果表明,CeO2的存在可控制Au颗粒的沉积并稳定载体上的纳米Au颗粒.Au/CeO2/HMS上CO低温氧化反应完全转化温度为60oC.高度分散的Au0可以活化CO,CeO2颗粒则可以提供反应需要的氧.稳定性测试结果显示,反应48h催化剂活性维持不变.
CeO2 / HMS composite support was obtained by calcination using small amount of CeO2 by wet impregnation with SiO2 (HMS) carrier with graded pore structure. Then Au nanoparticles were loaded by deposition precipitation to obtain Au / CeO2 / HMS ternary Composite catalyst.The structure of the catalyst was characterized by X-ray diffraction, temperature programmed reduction and in-situ infrared spectroscopy.The results show that the presence of CeO2 can control the deposition of Au particles and stabilize the nano-Au particles on the support.Au / CeO2 / HMS The complete conversion temperature of the low-temperature oxidation of CO is 60oC. The highly dispersed Au0 can activate CO and the CeO2 particles can provide the oxygen needed for the reaction. The stability test results show that the catalyst activity remains unchanged after 48h reaction.