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Development of Heterogeneous Metathesis Catalysts with Nanopores

纳米孔多相复分解催化剂的开发

基本信息

批准号：
18065004
负责人：
ONAKA Makoto
金额：
$ 21.25万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research on Priority Areas
财政年份：
2006
资助国家：
日本
起止时间：
2006 至 2009
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-18065004/
关键词：
協奏機能触媒不均一系メタセシス触媒メソポーラスアルミナ塩化亜鉛修飾メチルトリオキソレニウム官能基化オレフィンオレフィン・メタセシス反応触媒反応触媒調製化学触媒機能解析ナノ細孔塩化亜鉛メタセシス反応ルイス酸修飾 γ-アルミナ XAFS測定シリカアルミナメソ細孔構造

项目摘要

Olefin metathesis reactions have been performed by transition metal complexes or oxides of molybdenum and tungsten. Among heterogeneous catalysts for metathesis, it is well known that rhenium-based catalysts are powerful ones. For example, supported Re_2O_7 shows higher activity for liquid-phase metathesis reactions of simple olefins than MoO_3 and WO_3 catalysts. Although rhenium-based catalysts have high potential for olefin metathesis, they have serious drawbacks of little activity toward functionalized olefins without help of additives such as R4Sn and R4Pb. In 1991, organometallic methyltrioxorhenium (MTO) was reported to smoothly induce the metathesis of functionalized olefin only on the surface of a solid acid, SiO_2-Al_2O_3. However, the nature of the rhenium species and the role of the catalyst carrier, SiO_2-Al_2O_3, have not been fully illuminated. In this study, we found that a zinc chloride-modified mesoporous alumina, ZnCl_2//meso-Al_2O_3, with a high surface area, relatively uniform mesopores, and Lewis acidic character was developed, and that MTO doped on the alumina, MTO/ZnCl_2//meso-Al_2O_3, demonstrated higher catalytic performance for the metathesis of functionalized olefins than Herrmann's system of MTO on SiO_2-Al_2O_3 (MTO/SiO_2-Al_2O_3). In our catalytic system, ZnCl_2//meso-Al_2O_3 not only immobilizes MTO on its solid surface, but also activates MTO enough to accelerate the metathesis of functionalized olefins.

烯烃复分解反应已经通过钼和钨的过渡金属络合物或氧化物进行。在用于复分解的多相催化剂中，众所周知的是基于铱的催化剂是强有力的催化剂。例如，负载型Re_2O_7催化剂对简单烯烃的液相复分解反应表现出比MoO_3和WO_3催化剂更高的活性。尽管基于铱的催化剂具有高的烯烃复分解潜力，但是它们具有严重的缺点，即在没有添加剂如R4 Sn和R4 Pb的帮助下对官能化烯烃的活性很小。1991年，有机金属甲基三氧化铼（MTO）被报道仅在固体酸SiO_2-Al_2O_3表面上就能顺利地诱导官能化烯烃的复分解反应。然而，对催化剂载体SiO_2-Al_2O_3的作用以及催化剂中的活性组分的性质还没有完全阐明。本研究中，我们制备了一种具有高比表面积、相对均匀的介孔结构和刘易斯酸性的介孔氧化铝（ZnCl_2//meso-Al_2 O_3），并在此基础上制备了MTO/ZnCl_2//meso-Al_2 O_3，结果表明，该催化剂对官能化烯烃的歧化反应性能优于Herrmann的MTO/SiO_2-Al_2O_3体系（MTO/SiO_2-Al_2O_3）。ZnCl_2//meso-Al_2 O_3催化体系不仅能将MTO固定在固体表面，而且能充分活化MTO，促进功能化烯烃的歧化反应。