| 林景治,褚衍来,顾靖芳,杨得信,张传卫,杨英兰,李树本.对甲烷氧化偶联W－Mn／SiO＿2催化剂Na＿2WO＿4的流失及其影响的考察[J].分子催化,1996,(3): |
| 对甲烷氧化偶联W－Mn／SiO＿2催化剂Na＿2WO＿4的流失及其影响的考察 |
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| DOI： |
| 中文关键词: 甲烷氧化偶联Na_2WO_4Mn_2O_3流失 |
| 英文关键词:Methane, Oxidative couping, Na 2WO 4, Mn 2O 3, Loss |
| 基金项目:国家自然科学基金资助项目 |
| 林景治 褚衍来 顾靖芳 杨得信 张传卫 杨英兰 李树本 |
| 中国科学院兰州化学物理研究所 |
| 摘要点击次数: 1257 |
| 全文下载次数: 18 |
| 中文摘要: |
| 用ＸＲＤ、ＦＴ－ＩＲ、ＥＳＲ、Ｈ２－ＴＰＲ和ＴＰＯ等方法，对Ｎａ２ＷＯ４－Ｍｎ２Ｏ３／ＳｉＯ２催化剂和其经水煮处理的一系列样品进行了表征．实验发现该催化剂中的结晶态Ｎａ２ＷＯ４易于流失，单层分布的Ｎａ２ＷＯ４在苛刻的处理条件下也有可能流失．依此，探讨了上述流失现象与Ｎａ２ＷＯ４－Ｍｎ２Ｏ３／ＳｉＯ２催化剂的催化活性及该催化剂在长时间反应中发生的ＳｉＯ２相变之间的关系，证明了结晶态Ｎａ２ＷＯ４的流失对该催化剂甲烷氧化偶联反应的催化活性只有轻微的影响，单层分布Ｎａ２ＷＯ４的流失可造成催化剂中Ｍｎ从Ｍｎ３＋转变为Ｍｎ２＋，并使催化剂的催化活性明显降低．但在水煮条件下，无论是结晶态的还是单层分布，Ｎａ２ＷＯ４的流失都没有对ＳｉＯ２的α－方石英结构产生影响 |
| 英文摘要: |
| In this paper, the fresh and used Na 2WO 4 Mn 2O 3/SiO 2 catalysts and the samples treated in boiling water have been characterized by XRD, FT IR, ESR, H 2 TPR and O 2 TPO (Temperature programmed oxidation)techniques. The results show that the crystalline Na 2WO 4 phase is lost easily and monolayer distributed Na 2WO 4 is perhaps lost under the cruel conditions. The relations between Na 2WO 4 loss and catalyst activity as well as the SiO 2 phase transformation after long period reaction have been discussed. The studies indicate that the loss of crystalline Na 2WO 4 has little influence on the activity, but the loss of monolayer distributed Na 2WO 4 can result in the reduction of Mn 3+ to Mn 2+ causing the catalyst activity reduced markedly. However, the loss of either the crystalline or the monolayer Na 2WO 4 has no influence on the SiO 2 phase structure under the condition of boiling water treatment. |
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