以SBA-15为载体,采用沉积沉淀法制备了纳米Au催化剂,研究了不同预处理条件对Au在载体表面状态的影响,考察了催化剂样品催化CO氧化性能.以高分辨率透射电子显微镜、N2吸附、X射线衍射、紫外-可见漫反射吸收谱、X射线光电子能谱和电感耦合等离子体发射光谱等手段对催化剂的结构和表面性质进行了表征.结果表明,经还原焙烧处理后的Au/SBA-15催化剂热稳定性较好,Au在SBA-15孔道表面呈高分散状态,样品在CO氧化反应中表现出优异的低温催化活性和高温稳定性,同时具有优异的抗烧结性能和良好的循环稳定性.
The nano-Au catalyst samples were prepared by a facile deposition-precipitation method with SBA-15 as support,and the effects of pretreatment conditions and Au loading on the catalyst activity for CO oxidation were studied.The catalyst samples were characterized by high resolution transmission electron microscopy,N2 adsorption-desorption,X-ray diffraction,ultraviolet-visible diffuse reflectance spectroscopy,X-ray photoelectron spectroscopy,and inductively coupled plasma-atomic emission spectroscopy.The results showed that the Au particles were highly dispersed in the channels of SBA-15 after reduction and subsequent calcination.The sample pretreated by reduction and calcination exhibited high low-temperature activity and high catalytic activity when the reaction temperature was as high as 500 oC.The catalyst showed good cycle stability and high resistance to sintering.