The conversion of CO₂ from flue gas with epoxide [cycloaddition epoxide (CCE)] to produce cyclic carbonate is one of the important technologies to mitigate CO₂ emissions. In this context, a bifunctional mesoporous MOFs-based catalyst, Al-MDC-NC, was synthesized, which is composed of Al³⁺ Lewis acid sites and two nitrogen-containing mixed ligands that can capture CO₂. By grafting an N atom on the imidazole group to form a specific N-heterocyclic carbene-carboxylic adduct (NHC-CO₂) as the Lewis base site and introducing an electron-withdrawing group of NO₂ to enhance the Lewis acidity of the Al³⁺ sites, the carbon dioxide capture ability and the polarization of the epoxy substrate are improved in the absence of cocatalysts. The CCE reaction of CO₂ and epichlorohydrin shows a good catalytic effect, and a high conversion rate of 95.80% is obtained under mild and energy saving reaction conditions (100 °C, 10 h, and 1 bar). Interestingly, even for simulated dry and humid CO₂ flue gases, the conversion rates are as high as 90.35% and 83.99%, respectively. In addition, Al-MDC-NC, as a heterogeneous catalyst, shows a very robust structure and recyclability after five cyclic catalytic experiments. This study may provide an effective avenue for the production of value-added fine chemicals from industrial flue gas under actual ambient conditions using a ligand modification strategy.

中文翻译：

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在模拟环境条件下实现高效 CO2 转化的含氮混合配体修饰介孔金属-有机框架的设计


将_CO2 从带有环氧化物 [环加成环氧化物 （CCE）] 的烟气中转化为环状碳酸酯是减少_CO2 排放的重要技术之一。在此背景下，合成了一种基于双功能介孔 MOF 的催化剂 Al-MDC-NC，它由 Al³⁺ 路易斯酸位点和两个可以捕获 CO₂ 的含氮混合配体组成。通过在咪唑基团上接枝一个 N 原子以形成特定的 N-杂环卡宾-羧基加合物 （NHC-CO₂） 作为 Lewis 基位点，并引入 NO₂ 的吸电子基团以增强 Al³⁺ 位点的 Lewis 酸度，在没有助催化剂的情况下，二氧化碳捕获能力和环氧树脂基材的极化得到改善。CO₂ 与环氧氯丙烷的 CCE 反应表现出良好的催化作用，在温和节能的反应条件下（100 °C、10 h 和 1 bar）获得 95.80% 的高转化率。有趣的是，即使对于模拟的干燥和潮湿 CO₂ 烟气，转化率也分别高达 90.35% 和 83.99%。此外，Al-MDC-NC 作为一种非均相催化剂，经过 5 次循环催化实验后表现出非常稳健的结构和可回收性。本研究为在实际环境条件下使用配体修饰策略从工业烟气中生产增值精细化学品提供了一条有效的途径。