中国科学院大连化物所李灿团队报道了CO₂加氢过程中，可控的活性中间体通过N-甲酰化合成高选择性N，N-二甲基甲酰胺。相关研究成果发表在2024年12月19日出版的《美国化学会杂志》。

N、 N-二甲基甲酰胺（DMF）是一种应用广泛的溶剂，其绿色低碳合成方法需求量很大。

该文报道了一种使用固定床反应器和ZnO-TiO₂固溶体催化剂的连续流反应系统合成DMF的新方法。该催化剂有效地利用了CO₂、H₂和二甲胺（DMA）作为原料，具有99%DMF选择性和单程DMA转化率接近热力学平衡的性能。

此外，催化剂表现出良好的稳定性，在连续运行1000小时后没有失活迹象。高活性的关键在于锌和钛位点的协同作用，这有助于形成活性甲酸盐物种。这些物质作为关键中间体，与DMA反应生成DMF。重要的是，甲酸盐物种的缓慢氢化动力学阻止了CH2O*物种的形成，从而抑制了不希望的副产物三甲胺的形成。

该工作强调了动力学控制二氧化碳氢化中活性中间体的潜力，通过将其与平台分子偶联来制备高附加值的化学品。它为有效利用二氧化碳资源提供了一种有前景的策略，并为大规模DMF合成提供了有价值的解决方案。

附：英文原文

Title: Controllable Active Intermediate in CO2 Hydrogenation Enabling Highly Selective N,N-Dimethylformamide Synthesis via N-Formylation

Author: Jieyun Zhang, Guanna Li, Jin Xie, Yang Hai, Weiming Wan, Haotian Sun, Bin Wang, Xiaojing Wu, Jiannian Cheng, Changxin He, Wei Hu, Ying Zhang, Zelong Li, Can Li

Issue&Volume: December 19, 2024

Abstract: N,N-Dimethylformamide (DMF) is a widely used solvent, and its green and low-carbon synthesis methods are in high demand. Herein, we report a new approach for DMF synthesis using a continuous flow reaction system with a fixed-bed reactor and a ZnO-TiO2 solid solution catalyst. This catalyst effectively utilizes CO2, H2, and dimethylamine (DMA) as feedstocks, demonstrating performance with 99% DMF selectivity and single-pass DMA conversion approaching thermodynamic equilibrium. Moreover, the catalyst demonstrates good stability, with no signs of deactivation over 1000 h of continuous operation. The key to superior activity lies in the synergetic effect of the Zn and Ti sites, which facilitates the formation of active formate species. These species act as crucial intermediates, reacting with DMA to produce DMF. Importantly, the slow hydrogenation kinetics of the formate species prevent the formation of CH2O* species, thereby suppressing the formation of the undesired byproduct, trimethylamine. This work underscores the potential of kinetically controlling active intermediates in CO2 hydrogenation to prepare high-value-added chemicals by coupling them to platform molecules. It presents a promising strategy for the efficient utilization of CO2 resources and offers a valuable solution for large-scale DMF synthesis.

DOI: 10.1021/jacs.4c12503

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.4c12503