On-Line Analysis of the Heterogeneous Pd-Catalyzed Transfer Hydrogenation of p-Nitrophenol in Water with Formic Acid in a Flow Reactor,Organic Process Research & Development

当前位置： X-MOL 学术 › Org. Process Res. Dev. › 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.)

On-Line Analysis of the Heterogeneous Pd-Catalyzed Transfer Hydrogenation of p-Nitrophenol in Water with Formic Acid in a Flow Reactor
Organic Process Research & Development ( IF 3.1 ) Pub Date : 2019-12-12 , DOI: 10.1021/acs.oprd.9b00291
Xiaotong Zhan _{1,

2} , Sabine Michaud-Chevallier ₂ , Damien Hérault ₂ , Françoise Duprat ₁

Affiliation

An versatile experimental setup composed of a fixed-bed reactor and an HPLC apparatus has been developed for the study of heterogeneous catalytic reactions under transient conditions. The transfer hydrogen reaction of formic acid in water to give p-nitrophenol catalyzed by Pd@Al₂O₃ support was chosen as the model reaction in a flow reactor. On one hand, this setup allowed the first experimental on-line measurements of p-aminophenol in an acidic medium, indicating that it is the only product of the reaction at steady state. On the other hand, the setup evidenced a quite long transient period before stationary conditions were reached, involving a transient component that is quite instable and can transform to p-aminophenol without a catalyst. Results of numerical simulations indicate that only a change in the reaction mechanism, due to a change in the catalyst activity after few minutes of reaction, can explain the transient production of this intermediate and that this occurs when the active hydrogen coverage of the catalyst is low.

中文翻译：

流态反应器中甲酸对硝基苯在水中的对硝基苯酚的非均相Pd催化转移加氢在线分析。

已经开发了由固定床反应器和HPLC装置组成的通用实验装置，用于研究瞬态条件下的多相催化反应。在流动反应器中，以甲酸在水中的转移氢反应生成Pd @ Al ₂ O ₃载体催化的对硝基苯酚为模型反应。一方面，该设置允许在酸性介质中进行对氨基苯酚的首次实验在线测量，表明它是稳态下反应的唯一产物。另一方面，该设置证明在达到稳定状态之前有相当长的瞬态时间，其中涉及的瞬态分量非常不稳定，可以转换为p-氨基苯酚，无需催化剂。数值模拟结果表明，由于反应几分钟后催化剂活性的变化，只有反应机理的变化才能解释该中间体的瞬时生成，并且这种变化发生在催化剂的活性氢覆盖率较低时。

更新日期：2019-12-12

点击分享查看原文

点击收藏

阅读更多本刊最新论文本刊介绍/投稿指南11