| 丁云杰,梁东白.活化条件对负载Ru催化剂的Ru粒子化学环境的影响[J].分子催化(中英文),1993,(4):293-298 |
| 活化条件对负载Ru催化剂的Ru粒子化学环境的影响 |
| Effect of Activation Conditions on the Chemical Environment of Ru Crystallite of Supported Ru Catalyst |
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| DOI： |
| 中文关键词: 钌 催化剂 吸附 活化 |
| 英文关键词:Ru catalyst. Adsorption amount. Activation conditions. |
| 基金项目: |
| 丁云杰 梁东白 |
| 中国科学院大连化学物理研究所，中国科学院大连化学物理研究所，中国科学院大连化学物理研究所 大连116023杭州大学催化研究所，杭州310028.，大连116023，大连116023 |
| 摘要点击次数: 1052 |
| 全文下载次数: 20 |
| 中文摘要: |
| 本文应用动态脉冲吸附技术测定了H_2和CO的吸附量,结合透射电镜(TEM)和程序升温还原(TPR)等表征技术考察了活化条件对金属Ru粒子化学环境的影响.发现活化条件对Ru催化剂H_2和CO吸附量的影响很显著,H_2和CO低温吸附量随焙烧温度的升高而锐减;改由在惰性气体中焙烧或载体经HCI或HF预处理,大大增加了低温吸附量.TEM测定结果表明:金属Ru平均粒径(?)值随焙烧温度(在623K以下的范围内)的升高而减小,说明在此活化条件下处理的催化剂,其低温H_2和CO化学吸附量不能反映金属的分散度.TPR结果说明在空气中焙烧催化剂,Ru非氧化物前身转变成为RuO_2,并且导致金属与载体之间产生较强的相互作用,改变金属Ru粒子的化学环境,吸附活化能垒增高,在低温下H_2和CO的吸附量很小. |
| 英文摘要: |
| The influence of calcining condition, residual halide anion and adsorptive temperature on the amount of H2 and CO uptake over supported ruthenium catalysts was studied. It was found that H2 and CO uptake decreased gradually with enhancing of calcining temperature in air and dropped unexpectedly to zero beyound 523 K. The possibilities of sudden enlargement of the Ru crystallite siza with the calcining temperature and the site blocking by residual Cl- as the catalysts were prepared from RuCl3 precursor were ruled out. This phenomenon would be ascribed to the interaction between Ru metal and support. The interaction between RuO2 and support was strong, while that between nonoxide Ru compound and support was poor, before reduction. Due to the existence of halide anion in support, the transformation of Ru nonoxide precursor to RuO2 in the process of calcination in air. espccialy in a flow of He, could be prevented. The H2 and CO uptake was found to be multiplied as compared with that of the halide-free catalysts on account of the presence of halide anions in the catalysts. The amount of CO adsorbed was found to increase with the temperature of adsorption implying that the activation of some adsorption sites was required. |
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