Au/TiO 2 催化剂制备条件对巴豆醛选择加氢的影响
Au/TiO 2 催化剂制备条件对巴豆醛选择加氢的影响
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DOI：
10.3866/pku.whxb20090906
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发表时间：
2009-09
影响因子：
10.9
通讯作者：
杨秋芸;朱渊;田莉;裴燕;乔明华;范康年
中科院分区：
文献类型：
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作者：
杨秋芸;朱渊;田莉;裴燕;乔明华;范康年
采用沉积-沉淀法制备了纳米Au/TiO 2催化剂。通过巴豆醛液相加氢反应对催化剂进行了评价，并采用X射线衍射（XRD）、透射电子显微镜（TEM）和X射线光电子能谱（XPS）对催化剂进行了表征。通过改变活化气氛、Au负载和还原温度，我们发现Au颗粒的尺寸和金属-载体相互作用是容易调节的。当Au质量分数为9.2%，还原温度为673 K时，Au/TiO 2催化剂的平均粒径为2 nm，初始加氢速率高达13.7×10-5 mol·s-1·g-1，巴豆醇的最大收率为69.9%.结合表征结果，认为该催化剂的上级性能主要是由于其具有最佳的粒径和对Au纳米粒子的电子修饰作用。这是由于在还原过程中在TiO 2上产生的氧缺陷。
Nanosized Au/TiO2 catalysts were prepared by the deposition-precipitation method. These catalysts were evaluated by a liquid phase hydrogenation of crotonaldehyde to crotyl alcohol and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). By changing the activation atmosphere, the Au loading, and the reduction temperature we found that the dimension of the Au particles and the metal-support interaction were readily adjustable. For the Au/TiO2 catalyst reduced at 673 K with an optimal Au mass fraction of 9.2%, the mean particle size of Au was 2 nm and the initial hydrogenation rate was as high as 13.7×10-5 mol·s-1·g-1, while the maximum yield of crotyl alcohol was 69.9%. Combined with the characterization results, the superior performance of this catalyst was attributed to it having an optimal size and to its electronic modification effects on the Au nanoparticles. This was due to oxygen defects generated on the TiO2 during the reduction process.