| 余锡宾,王桂华.Pd—B／SiO2非晶态合金的晶化过程及其催化加氢活性的研究[J].分子催化,1999,(5):351-356 |
| Pd—B／SiO2非晶态合金的晶化过程及其催化加氢活性的研究 |
| Study on the Crystallization Process of Pd-B/SiO_2 Amorphous Alloy Catalyst and its Hydrogenation Activity |
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| DOI： |
| 中文关键词: 非晶态合金 晶化 催化加氢活性 催化剂载体 |
| 英文关键词:Pd\|B/SiO 2 amorphous alloy,Crystallization process,Hydrogenation activity |
| 基金项目:上海市教委重点学科基金 |
| 余锡宾 王桂华 |
| 上海师范大学化学系!上海200234 |
| 摘要点击次数: 1217 |
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| 中文摘要: |
| 用Ｒａｍａｎ，ＸＲＤ，ＳＥＭ等技术，研究了Ｐｄ－Ｂ／ＳｉＯ２非晶态合金的晶化过程及其对催化活性的影响。研究发现，Ｐｄ＾２＋能高度分散在ＳｉＯ２载体上，并与载体发生作用，但Ｐｄ－Ｂ合金在载体上形成颗粒微细的原子簇，温度低于６７３Ｋ时，这些原子簇在ＳｉＯ２载体上呈非晶态结构，并随着温度的增加而发生团聚。 |
| 英文摘要: |
| The crystallization process of Pd\|B/SiO 2 amorphous alloy and its effect on the hydrogenation activity were investigated based on the various characterizations, such as Raman, XRD, SEM, hydrogen chemisorption. It was found that Pd 2+ is highly dispersed on the silica support and the Pd\|B amorphous alloy is formed as atom clusters in ultrafine particles at temperature lower than 673 K. The alloy particles gradually gathered with the increase of temperature . The phase decomposition and crystallization of Pd\|B alloy occur at temperature around 673 K. Its active surface area decreased in crystallization process, which, in turn, resulted in the decrease in its nitrobenzene hydrogenation activity. As Pd has been proved to be the active centers for hydrogenation, the promoting effect of B on the hydrogenation activity can be mainly attributed to its alloying effect with Pd to form the favorite amorphous structure and surface electronic states. The promoting effect of silica support could be understood by considering the increase of the surface area of the catalyst and improvement of thermal stability of the Pd\|B amorphous structure owing to the high dispersion of the Pd\|B alloy particles on the support. |
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