中文摘要：

通过KBH4还原浸渍到载体上的Pd物种制备了超细Pd/γ-Al2O3催化剂，并采用X射线衍射、高倍透射电镜、能谱、能量损失谱和电感耦合等离子体发射光谱等对其进行了表征．结果表明，催化剂中活性组分Pd以纳米尺度的微晶形式存在，而不是Pd—B非晶态合金．蒽醌加氢制双氧水反应证明，与浸渍焙烧法制备的Pd/γ-Al2O3催化剂相比，经KBH4还原制得的Pd/γ-Al2O3催化剂中钯的晶体颗粒更小，分散度更高，从而催化剂的活性更高，其氢化效率比Pd/γ-Al2O3提高了35％．

英文摘要：

The ultrafine Pd/γ-Al2O3 catalyst was prepared by impregnation of alumina support with PdCl2 solution followed by KBH4 reduction. The microstructure of Pd/γ-Al2O3 was investigated by X-ray diffraction, high resolution electron microscopy, energy dispersive spectroscopy and electron energy loss spectroscopy. The results show that the Pd species exists as Pd nanocrystals in the as-prepared catalyst, and no Pd-B amorphous alloy was found. Compared with the Pd/γ-Al2O3 catalyst prepared by impregnation and calcination, the ultrafine Pd/γ-Al2O3 exhibits higher activity in the hydrogenation of 2-ethylanthraquinone. This can be attributed to the unique properties of the ultrafine Pd/γ-Al2O3, such as smaller Pd crystals and the higher dispersion of Pd on the support.