Luo Jingjie, Liu Pengcheng, Yang Wenhao, Niu Hongyu, Li Shaojie, Liang Changhai
Laboratory of Advanced Materials & Catalytic Engineering (AMCE), School of Chemical Engineering, Dalian University of Technology, Panjin, China.
Front Chem. 2022 Jul 22;10:945028. doi: 10.3389/fchem.2022.945028. eCollection 2022.
The carbonylative transformation of ethylene oxide (EO) into methyl 3-hydroxypropionate (3-HPM) is a key process for the production of 1,3-propanediol (1,3-PDO), which is currently viewed as one of the most promising monomers and intermediates in polyester and pharmaceuticals industry. In this work, a homogeneous reaction system using commercial Co(CO) was first studied for the carbonylation of EO to 3-HPM. The catalytic behavior was related to the electronic environment of N on aromatic rings of ligands, where N with rich electron density induced a stronger coordination with Co center and higher EO transformation. A reaction order of 2.1 with respect to EO and 0.3 with respect to CO was unraveled based on the kinetics study. The 3-HPM yield reached 91.2% at only 40°C by Co(CO) coordinated with 3-hydroxypyridine. However, Co-containing colloid was formed during the reaction, causing the tough separation and impossible recycling of samples. Concerning the sustainable utilization, Co particles immobilized on pre-treated carbon nanotubes (Co/CNT-C) were designed an reduced colloid method. It is remarkable that unlike conventional Co/CNT, Co/CNT-C was highly selective toward the transformation of EO to 3-HPM with a specific rate of 52.2 , displaying a similar atomic efficiency to that of coordinated Co(CO). After reaction, the supported Co/CNT-C catalyst could be easily separated from the liquid reaction mixture, leading to a convenient cyclic utilization.
环氧乙烷（EO）羰基化转化为3-羟基丙酸甲酯（3-HPM）是生产1,3-丙二醇（1,3-PDO）的关键过程，1,3-丙二醇目前被视为聚酯和制药行业中最有前景的单体和中间体之一。在这项工作中，首先研究了使用商业Co(CO)的均相反应体系用于EO羰基化制备3-HPM。催化行为与配体芳环上N的电子环境有关，其中富电子密度的N与Co中心诱导更强的配位作用以及更高的EO转化率。基于动力学研究得出EO的反应级数为2.1，CO的反应级数为0.3。通过Co(CO)与3-羟基吡啶配位，在仅40°C时3-HPM产率达到91.2%。然而，反应过程中形成了含Co胶体，导致样品分离困难且无法循环利用。关于可持续利用，通过还原胶体法设计了负载在预处理碳纳米管上的Co颗粒（Co/CNT-C）。值得注意的是，与传统的Co/CNT不同，Co/CNT-C对EO转化为3-HPM具有高度选择性，比速率为52.2 ，显示出与配位Co(CO)相似的原子效率。反应后，负载型Co/CNT-C催化剂可轻松从液体反应混合物中分离，便于循环利用。
