ZnO负载纳米金催化剂上的低温水煤气变换反应

Low-Temperature Water-Gas Shift Reaction over ZnO-Supported Gold Nanoparticle Catalyst

系统考察了各种制备参数对ZnO负载的纳米金催化剂上低温水煤气变换反应性能的影响.结果表明,不同的制备方法、沉淀剂种类、焙烧温度及金负载量均对催化剂的催化性能有较大的影响.以Na2CO3为沉淀剂,采用共沉淀法,经240℃焙烧制备的金含量为5%的样品上表现出最佳的低温水煤气变换反应性能.X射线衍射、N2吸附和透射电镜测试结果表明,制备参数的变化会影响金物种的分散状态、载体的粒径或比表面积的大小,从而影响催化剂的催化活性.适量氯离子的存在对催化剂活性也有明显的促进作用.

The effects of preparation methods and conditions on the catalytic performance of the ZnO-supported gold nanoparticle catalyst （Au/ZnO） were investigated for low-temperature water-gas shift （WGS） reaction. It was found that the catalytic performance of Au/ZnO could be considerably influenced by various factors, such as preparation methods, precipitant types, calcination temperature and gold loading. Among the catalyst samples, the 5% Au/ZnO sample prepared by the co-precipitation method using Na2CO3 as precipitant and calcined at 240 ℃ exhibited the highest activity for the WGS reaction. The results of X-ray diffraction, N2 adsorption and transmission electron microscopy suggested that the change of preparation parameters could affect the dispersion state of gold species and the size or the specific surface area of the ZnO support, thus considerably influenced the catalytic activity of the Au/ZnO catalyst. Moreover, the existence of a moderate amount of Cl ions in the catalyst might also have a positive effect on the catalytic performance of the catalyst.