In this study, we have for the first time demonstrated that succinimide (SI)-KI is an efficient catalyst system to synthesize propylene carbonate (PC) from carbon dioxide (CO₂) and propylene oxide (PO) at a solvent-free condition. A synergistic effect was observed between SI and KI that largely increased the reaction yield. It enabled the cycloaddition reaction to take place at 70 °C under a low pressure (0.4 MPa) for only 4 h, with a PC yield as high as 97.5%. The overall condition is milder than the reaction catalyzed by most of the other KI involved co-catalyst systems reported in literatures. The excellent catalytic ability was explained by the increased KI solubility in PO due to the presence of SI and the weak acidity of NH in SI which can be enhanced by KI. A reaction mechanism was proposed based on a reaction kinetics study. SI-KI was applicable to cycloaddition of CO₂ with other epoxides. It may offer an inexpensive, environmentally-friendly route to synthesis of propylene carbonate from CO₂.

在这项研究中，我们首次证明了琥珀酰亚胺（SI）-KI是一种有效的催化剂体系，可以从二氧化碳（CO ₂）和环氧丙烷（PO）在无溶剂的条件下使用。在SI和KI之间观察到协同作用，这大大提高了反应产率。它使环加成反应能够在70°C的低压（0.4 MPa）下仅进行4小时，PC产率高达97.5％。总体条件比文献中报道的大多数其他涉及KI的助催化剂体系催化的反应温和。优异的催化能力是由于SI的存在导致KI在PO中的溶解度增加以及NH在SI中的弱酸度所引起的，KI可以增强KI的溶解度。基于反应动力学研究提出了反应机理。SI-KI适用于CO _2的环加成与其他环氧化物。它可以提供从CO ₂合成碳酸亚丙酯的廉价，环境友好的途径。