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多相Rh-WOx对位点催化剂上的双官能氢甲酰化反应
作者:小柯机器人 发布时间:2022/9/10 15:20:27

美国加州大学Christopher, Phillip团队报道了多相Rh-WOx对位点催化剂上的双官能氢甲酰化反应。相关研究成果发表在2022年9月7日出版的国际学术期刊《自然》。

金属催化反应通常假设在双功能活性位点上进行,因此共定位的反应物种促进催化循环中的不同基本步骤。双功能活性点已在均相双核有机金属催化剂上建立。有经验证据表明负载型金属催化剂上存在双功能活性位,例如,在金属-氧化物载体界面。然而,由于潜在活性位点结构的分布、其动态重建和所需的非平均场动力学描述,阐明载体金属催化剂上的双功能反应机制具有挑战性。

研究人员通过合成负载的、原子分散的铑-钨氧化物(Rh-WOx)对位点催化剂克服了这些限制。相对简单的配对位点结构和充分的描述通过平均场建模使实验动力学与基于第一性原理的微动力学模拟相关联。Rh-WOx对位点通过双功能机制催化乙烯氢甲酰化,包括Rh辅助的WOx还原、乙烯从WOx转移到Rh以及Rh-WOx界面处的H2解离。在气相乙烯氢甲酰化反应中,产物生成速率为0.1g丙二醛cm-3h-1时,成对位点显示出>95%的选择性。

研究结果表明,氧化物负载的对位点可以实现双功能反应机制,对于工业上使用均相催化剂进行的反应具有高活性和选择性。

附:英文原文

Title: Bifunctional hydroformylation on heterogeneous Rh-WOx pair site catalysts

Author: Ro, Insoo, Qi, Ji, Lee, Seungyeon, Xu, Mingjie, Yan, Xingxu, Xie, Zhenhua, Zakem, Gregory, Morales, Austin, Chen, Jingguang G., Pan, Xiaoqing, Vlachos, Dionisios G., Caratzoulas, Stavros, Christopher, Phillip

Issue&Volume: 2022-09-07

Abstract: Metal-catalysed reactions are often hypothesized to proceed on bifunctional active sites, whereby colocalized reactive species facilitate distinct elementary steps in a catalytic cycle1,2,3,4,5,6,7,8. Bifunctional active sites have been established on homogeneous binuclear organometallic catalysts9,10,11. Empirical evidence exists for bifunctional active sites on supported metal catalysts, for example, at metal–oxide support interfaces2,6,7,12. However, elucidating bifunctional reaction mechanisms on supported metal catalysts is challenging due to the distribution of potential active-site structures, their dynamic reconstruction and required non-mean-field kinetic descriptions7,12,13. We overcome these limitations by synthesizing supported, atomically dispersed rhodium–tungsten oxide (Rh-WOx) pair site catalysts. The relative simplicity of the pair site structure and sufficient description by mean-field modelling enable correlation of the experimental kinetics with first principles-based microkinetic simulations. The Rh-WOx pair sites catalyse ethylene hydroformylation through a bifunctional mechanism involving Rh-assisted WOx reduction, transfer of ethylene from WOx to Rh and H2 dissociation at the Rh-WOx interface. The pair sites exhibited >95% selectivity at a product formation rate of 0.1gpropanalcm3h1 in gas-phase ethylene hydroformylation. Our results demonstrate that oxide-supported pair sites can enable bifunctional reaction mechanisms with high activity and selectivity for reactions that are performed in industry using homogeneous catalysts.

DOI: 10.1038/s41586-022-05075-4

Source: https://www.nature.com/articles/s41586-022-05075-4

期刊信息

Nature:《自然》,创刊于1869年。隶属于施普林格·自然出版集团,最新IF:42.778
官方网址:http://www.nature.com/