Zhang Ying, Kang Dafei, Aindow Mark, Erkey Can
Department of Chemical Engineering, Environmental Engineering Program, University of Connecticut, Storrs, Connecticut 06269, USA.
J Phys Chem B. 2005 Feb 24;109(7):2617-24. doi: 10.1021/jp0467595.
Carbon-aerogel-supported ruthenium nanoparticles were synthesized by impregnating carbon aerogels with Ru(acac)3 or Ru(cod)(tmhd)2 from supercritical carbon dioxide (scCO2) solutions, followed by thermal reduction of these precursors. Two different carbon aerogels with pore diameters of 4 and 21 nm were synthesized. The kinetics and the thermodynamics of impregnation of carbon aerogels with the ruthenium coordination complexes were studied. The approach-to-equilibrium data indicated very fast adsorption, and the adsorption isotherms were found to follow the Langmuir model. The impregnated carbon aerogel complexes were reduced thermally at different temperatures between 300 and 1000 degrees C in the presence of nitrogen. The resulting nanocomposites were characterized using transmission electron microscopy (TEM) and hydrogen chemisorption. TEM micrographs showed that the ruthenium nanoparticles were dispersed homogeneously throughout the porous carbon aerogel matrix, and the average sizes obtained under different conditions ranged from 1.7 to 3.8 nm. Once complete decomposition of the precursor had been achieved, the mean size of the ruthenium particles increased with increasing reduction temperature.
通过用超临界二氧化碳（scCO₂）溶液中的Ru(acac)₃或Ru(cod)(tmhd)₂浸渍碳气凝胶，随后对这些前驱体进行热还原，合成了碳气凝胶负载的钌纳米颗粒。合成了两种不同孔径分别为4纳米和21纳米的碳气凝胶。研究了碳气凝胶与钌配位络合物浸渍的动力学和热力学。接近平衡的数据表明吸附非常快，并且发现吸附等温线符合朗缪尔模型。在氮气存在下，将浸渍的碳气凝胶络合物在300至1000摄氏度之间的不同温度下进行热还原。使用透射电子显微镜（TEM）和氢化学吸附对所得纳米复合材料进行表征。TEM显微照片显示钌纳米颗粒均匀地分散在整个多孔碳气凝胶基质中，在不同条件下获得的平均尺寸范围为1.7至3.8纳米。一旦前驱体完全分解，钌颗粒的平均尺寸随着还原温度的升高而增加。
