• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >Ruthenium-based ionic hydrogenation catalysts for the selective deoxygenation of biomass-derived feedstocks.
【24h】

Ruthenium-based ionic hydrogenation catalysts for the selective deoxygenation of biomass-derived feedstocks.

机译：钌基离子氢化催化剂，用于生物质衍生原料的选择性脱氧。

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

A series of ruthenium-based homogeneous ionic hydrogenation catalysts and their application in the selective deoxygenation under acidic conditions of glycerol, levulinic acid, anhydroerythritol, and 5-hydroxymethylfurfural was investigated. The syntheses of the five acid- and water-stable catalysts cis-[Ru(N--N)2(OH2)2](OTf) 2, [Cp*Ru(OH2)(N--N)](OTf), and mer-[Ru(OH 2)3(terpy)](OTf)2 (Cp* = C5Me 5-; N--N = 2,2'-bipyridine, 1,10-phenanthroline; OTf = CF3SO3-; terpy = 2,2':6',2"-terpyridine) are described. An improved, two-step synthesis of 6,6'-diamino-2,2'-bipyridine (dabp) was developed and synthetic efforts towards cis-[Ru(dabp) 2(OH2)2](OTf)2 and [Cp*Ru(OH2 )(dabp)](OTf) are discussed.;The five catalysts were tested as hydrogenation catalysts for carbonyl model substrates. Aldehydes were readily hydrogenated, while activity in ketone hydrogenations scaled inversely with the steric demand of the catalyst and ketone. The [Cp*Ru(OH2)(N--N)](OTf) catalysts were the least active while [Ru(OH2)3(terpy)](OTf)2 was the most active. Deoxygenation studies of the model substrate 1,2-hexanediol showed that [Ru(N--N)2(OH2)2](OTf) 2 and [Ru(OH2)3(terpy)](OTf)2 were stable to 175 °C, while the [Cp*Ru(OH2)(N--N)](OTf) systems were stable to at least 200 °C. Substrate condensation reactions dominated at reaction temperatures greater than 150 °C. The addition of water alleviated this problem to a certain extent, but also resulted in decreased catalytic activity. [Ru(OH2)3(terpy)](OTf) 2 was found to be very active, completely deoxygenating 1,2-hexanediol to hexane.;The [Cp*Ru(OH2)(N--N)](OTf) and [Ru(OH2) 3(terpy)](OTf)2 catalysts were tested for the selective deoxygenation of glycerol to 1,3-propanediol. 1-Propanol was produced in up to 18% yield, but no 1,3-propanediol was observed. The bulk of the glycerol was consumed in condensation reactions. Control experiments proved that the desired pathway of glycerol to 1,3-propanediol (and further deoxygenation to 1-propanol or even propane) was not the operative pathway. Instead, glycerol was dehydrated to acrolein, which was subsequently hydrogenated to 1-propanol.;Levulinic acid was hydrogenated to gamma-valerolactone in 80% yield. Trace amounts of tetrahydrofuran were obtained from anhydroerythritol, but in general, little hydrogenation activity was observed for this substrate.;The presence of high concentrations of acid and/or water in reaction mixtures containing 5-hydroxymethylfurfural led either to hydration and fragmentation to levulinic acid and subsequent hydrogenation to gamma-valerolactone, or to polymerization and decomposition. With less acid, nearly complete conversion of 5-hydroxymethylfurfural was observed. Identified hydrogenation products included 2,5-hexanedione and 2,5-bis(hydroxymethyl)furan.
机译：研究了一系列钌基均相离子加氢催化剂及其在酸性条件下对甘油，乙酰丙酸，脱水赤藓糖醇和5-羟甲基糠醛的选择性脱氧的应用。五个酸和水稳定催化剂cis- [Ru（N-N）2（OH2）2]（OTf）2 [[Cp * Ru（OH2）（N--N）]（OTf）的合成，和mer- [Ru（OH 2）3（terpy）]（OTf）2（Cp * = C5Me 5-; N--N = 2,2'-联吡啶，1,10-菲咯啉; OTf = CF3SO3-;描述了一种三联体合成改进的6,6'-二氨基-2,2'-联吡啶（dabp），并尝试了顺式-讨论了[Ru（dabp）2（OH2）2]（OTf）2和[Cp * Ru（OH2）（dabp）]（OTf）。;测试了五种催化剂作为羰基模型底物的加氢催化剂。氢化时，酮氢化的活性与催化剂和酮的空间需求成反比，[Cp * Ru（OH2）（N--N）]（OTf）催化剂的活性最低，而[Ru（OH2）3（ terpy）]（OTf）2最为活跃，对模型底物1,2-己二醇的脱氧研究表明，[Ru（N--N）2（OH2）2]（OTf）2和[Ru（OH2）3 （terpy）]（OTf）2稳定在175°C，而[Cp * Ru（OH2）（N--N）]（OTf）体系稳定表温度至少为200°C。底物缩合反应在高于150°C的反应温度下占主导地位。加水在一定程度上减轻了该问题，但也导致催化活性下降。发现[Ru（OH2）3（terpy）]（OTf）2具有很高的活性，可以将1,2-己二醇完全脱氧为己烷。[Cp * Ru（OH2）（N--N）]（OTf）测试了[Ru（OH2）3（terpy）]（OTf）2催化剂对甘油选择性脱氧为1,3-丙二醇的能力。 1-丙醇的产率高达18％，但是没有观察到1,3-丙二醇。大部分甘油在缩合反应中被消耗。对照实验证明，甘油转化为1,3-丙二醇的所需途径（以及进一步脱氧为1-丙醇甚至丙烷的途径）不是有效途径。取而代之的是，将甘油脱水为丙烯醛，然后将其氢化为1-丙醇。将叶绿酸以80％的产率氢化为γ-戊内酯。从脱水赤藓糖醇中获得痕量的四氢呋喃，但通常观察到该底物的氢化活性很小。含有5-羟甲基糠醛的反应混合物中存在高浓度的酸和/或水会导致水合和碎裂为乙酰丙酸然后氢化为γ-戊内酯，或进行聚合和分解。用较少的酸，观察到5-羟甲基糠醛几乎完全转化。鉴定的氢化产物包括2，5-己二酮和2，5-双（羟甲基）呋喃。

著录项

  • 作者

    Thibault, Michelle Elizabeth.;

  • 作者单位

    University of Guelph (Canada).;

  • 授予单位 University of Guelph (Canada).;
  • 学科 Chemistry Inorganic.
  • 学位 Ph.D.
  • 年度 2009
  • 页码 230 p.
  • 总页数 230
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 无机化学;
  • 关键词

  • 入库时间 2022-08-17 11:38:26

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号