Effects of Alkali‐Metal Ions and Counter Ions in Sn‐Beta‐Catalyzed Carbohydrate Conversion,ChemSusChem

当前位置： X-MOL 学术 › ChemSusChem › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Effects of Alkali‐Metal Ions and Counter Ions in Sn‐Beta‐Catalyzed Carbohydrate Conversion
ChemSusChem ( IF 7.5 ) Pub Date : 2018-03-13 , DOI: 10.1002/cssc.201702413
Samuel G. Elliot ₁ , Søren Tolborg ₂ , Robert Madsen ₁ , Esben Taarning ₂ , Sebastian Meier ₁

Affiliation

Alkali‐metal ions have recently been shown to strongly influence the catalytic behavior of stannosilicates in the conversion of carbohydrates. An effect of having alkali‐metal ions present is a pronounced increase in selectivity towards methyl lactate. Mechanistic details of this effect have remained obscure and are herein addressed experimentally through kinetic experiments and isotope tracking. The presence of alkali‐metal ions has a differential effect in competing reaction pathways and promotes the rate of carbon–carbon bond breakage of carbohydrate substrates, but decreases the rates of competing dehydration pathways. Further addition of alkali‐metal ions inhibits the activity of Sn‐Beta in all major reaction pathways. The alkali‐metal effects on product distribution and on the rate of product formation are similar, thus pointing to a kinetic reaction control and to irreversible reaction steps in the main pathways. Additionally, an effect of the accompanying basic anions is shown, supposedly facilitating the cation exchange and eliciting a different concentration‐dependent effect to that of neutral alkali‐metal salts.

中文翻译：

碱金属离子和抗衡离子在Sn催化碳水化合物转化中的作用

最近显示出碱金属离子在碳水化合物的转化中强烈影响锡硅酸盐的催化行为。存在碱金属离子的影响显着提高了对乳酸甲酯的选择性。这种作用的机械细节仍然不清楚，这里通过动力学实验和同位素追踪实验性地解决。碱金属离子的存在在竞争反应途径中具有不同的作用，并提高了碳水化合物底物的碳-碳键断裂速率，但降低了竞争脱水途径的速率。进一步添加碱金属离子会抑制Sn-Beta在所有主要反应路径中的活性。碱金属对产品分布和产品形成速率的影响相似，因此指向动力学反应控制和主要途径中不可逆的反应步骤。此外，还显示了伴随的碱性阴离子的作用，据推测可以促进阳离子交换并引起与中性碱金属盐不同的浓度依赖性效应。

更新日期：2018-03-13

点击分享查看原文

点击收藏

公开下载

阅读更多本刊最新论文本刊介绍/投稿指南11