The Academy of Fundamental and Interdisciplinary Science, Harbin Institute of Technology, Harbin, Heilongjiang 150080, People's Republic of China.
Nanoscale. 2013 Jul 7;5(13):5896-904. doi: 10.1039/c3nr01470c. Epub 2013 May 23.
Yolk-shell composites with a movable Fe(x)O(y) core and mesoporous SiO2 (mSiO2) shell, together with Pd nanoparticles uniformly anchoring on the inner surface, were prepared. The structure and composition of as-prepared catalysts were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Brunauer-Emmett-Teller measurement and Fourier-transform infrared spectroscopy, respectively. They are ideal candidates as nanoreactors for heterogeneous catalysis due to their special structure. The catalytic performance of Fe(x)O(y)/Pd@mSiO2 composites was studied by the reduction of 4-nitrophenol with NaBH4 as a reducing agent. Their reaction rate constant was calculated according to the pseudo-first-order reaction equation. The catalysts could be easily recycled by an external magnetic field due to their superparamagnetic property. Besides good catalytic property, another merit of Fe(x)O(y)/Pd@mSiO2 composites was high stability. We have compared the stability between Fe(x)O(y)/Pd@mSiO2 and Fe3O4@C/Pd composites by ultrasonic treatment and HNO3 solution etching, the stability of the former was much better than the later.
具有可动 Fe(x)O(y) 核和介孔 SiO2（mSiO2）壳的蛋黄壳复合材料，以及均匀锚定在内部表面的 Pd 纳米粒子，被制备出来。通过扫描电子显微镜、透射电子显微镜、X 射线衍射、X 射线光电子能谱、BET 测量和傅里叶变换红外光谱分别对所制备的催化剂的结构和组成进行了表征。由于其特殊的结构，它们是作为多相催化用纳米反应器的理想候选物。通过用 NaBH4 作为还原剂还原 4-硝基苯酚来研究 Fe(x)O(y)/Pd@mSiO2 复合材料的催化性能。根据准一级反应方程计算了它们的反应速率常数。由于超顺磁性，催化剂可以很容易地通过外部磁场进行回收。除了良好的催化性能外，Fe(x)O(y)/Pd@mSiO2 复合材料的另一个优点是高稳定性。我们通过超声处理和 HNO3 溶液刻蚀比较了 Fe(x)O(y)/Pd@mSiO2 和 Fe3O4@C/Pd 复合材料之间的稳定性，前者的稳定性明显优于后者。
