Synthesis of complex metal cluster and creation of new synergy

复杂金属团簇的合成及新协同效应的创造

基本信息

批准号：
06453099
负责人：
YAMADA Muneyoshi
金额：
$ 4.99万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1996
项目状态：
已结题

项目摘要

For the purpose of uncovering the cause of synergy at molecular level, creation of new synergy was attempted using a complex metal cluster synthesized from chelating agent, metal complex and metal ion. We found the promoting effect of nitrilotriacetic acid (NTA)on hydrodesulfrization (HDS) activity of cobalt-molybdenum/alumina (Co-Mo/Al_2O_3) catalyst. Selective synthesis of synergistic site (active site) was enhanced when Co-Mo/Al_2O_3 catalysts were prepared by an impregnation method using NTA as chelating agent. In this study it was found that EDTA and trans-1,2-cyclohexane diamine-N,N,N^1, N^1-tetra-acetic acid (CyDTA) shows higher promoting effect. HDS activity of Cy-DTA-Co-Mo/Al_2O_3 was 70% higher than that of Co-Mo/Al_2O_3. Incorporation of these chelated complex into zeolite cage nor synthesis of complex chelate cluster in the cage was not confirmed.In order to inverstigate the mechanism of activity promotion, IR spectra were measured to examine the behavior of adsorbed NO on … More the promoter and Mo sites. Mo K-edge EXAFS was also measured for clarify the local structure of active site. While HDS activity per CUS was increased, the effect of chelating agent vary greatly in dispersion of MoS2 cluster which is presumed to support the active site under reaction conditions, and in the number of coordinatively unsaturated site (CUS). It was suggested that highly dispersed cobalt is essential for formation of active site. Thus, it was demonstrated that dispersion of coblat is enhanced by chelating agent without changing local structure of active site.HDS activity of nickel-molybdenum/alumina (Ni-Mo/Al_2O_3) and nickel-tungsten/alumina (Ni-W/Al_2O_3) was compared with that of Co-Mo/Al_2O_3. While in the case of Ni-Mo/Al_2O_3, HDS activity was not influenced by NTA nor CyDTA addition, that of Cy-DTA-Ni-W/Al_2O_3 was 60% higher than that of Ni-W/Al_2O_3. The result shows that combination of metal ion is one of an important factor for the promotion effect of chelating agent. Less

为了在分子水平上揭示协同作用的原因，我们尝试使用由螯合剂、金属络合物和金属离子合成的复合金属簇来创造新的协同作用，我们发现了次氮基三乙酸（NTA）对加氢脱硫（HDS）的促进作用。 ) 选择性合成协同位点(活性位点)时，钴-钼/氧化铝(Co-Mo/Al_2O_3)催化剂的活性增强。以NTA为螯合剂，采用浸渍法制备了Co-Mo/Al_2O_3催化剂。乙酸(CyDTA)对Cy-DTA-Co-Mo/Al_2O_3的HDS活性具有较高的促进作用，比Cy-DTA-Co-Mo/Al_2O_3的HDS活性高70%。 Co-Mo/Al_2O_3 没有证实这些螯合络合物掺入沸石笼中，也没有证实笼中复合螯合物簇的合成。为了研究活性促进的机制，测量了红外光谱以检查吸附 NO 的行为......还测量了更多的启动子和 Mo K 边缘 EXAFS，以澄清活性位点的局部结构。虽然每个 CUS 的 HDS 活性增加，但螯合剂的效果差异很大。推测在反应条件下支持活性位点的MoS2簇的分散性以及配位不饱和位点（CUS）的数量表明，高度分散的钴对于活性位点的形成至关重要。螯合剂在不改变活性位点局部结构的情况下增强钴的活性。镍-钼/氧化铝(Ni-Mo/Al_2O_3)和的HDS活性镍-钨/氧化铝(Ni-W/Al_2O_3)与Co-Mo/Al_2O_3的HDS活性进行了比较，而在Ni-Mo/Al_2O_3的情况下，HDS活性不受NTA和CyDTA添加的影响，而Cy-DTA的影响较小。 -Ni-W/Al_2O_3比Ni-W/Al_2O_3的金属离子结合率高60%。少是螯合剂促进效果的重要因素之一。