CAJ | 학술논문

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60℃.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.
채용구유분등급공도결구적SiO2(HMS)위재체,통과윤습침지인입소량CeO2,경배소득도CeO2/HMS복합재체,연후채용침적침정법부재상Au납미입자,득도Au/CeO2/HMS삼원복합최화제.통과X사선연사、정서승온환원화원위홍외광보등수단표정료최화제적결구.결과표명,CeO2적존재가공제Au과립적침적병은정재체상적납미Au과립.Au/CeO2/HMS상CO저온양화반응완전전화온도위60℃.고도분산적Au0가이활화CO,CeO2과립칙가이제공반응수요적양.은정성측시결과현시,반응48h최화제활성유지불변.
Hierarchical composite nanostructure composed of Au,CeO2,and SiO2 was fabricated by sequentially depositing ceria nanoparticles through impregnation and calcination,and then gold nanoparticles through a deposition-precipitation method on hierarchical monolithic silica (HMS) with multi-length scale pore structure.The Au/CeO2/HMS composite nanostructure was characterized by X-ray diffraction,temperature-programmed reduction,and diffuse reflectance infrared Fourier transform spectroscopy.The results indicate that the presence of ceria had a significant effect on targeted deposition and stabilization of small metallic gold nanoparticles on the support.The temperature for complete conversion of CO to CO2 over Au/CeO2/HMS is ca.60 ℃ at a space velocity of 80000 ml/(g·h).The highly dispersed metallic gold nanoparticles can activate CO and the small ceria nanoparticles supply oxygen in the reaction.The catalytic activity remains considerably stable during 48 h stability testing.The interaction between gold and ceria contributed greatly to CO oxidation and the presence of silica improved the stability of the gold catalyst.