Selective capture of CO₂ from offgas is highly important for our sustainability, including mitigating global warming. Here, we investigated the CO₂ and N₂ adsorption under low pressure by using a mesoporous Zr-based metal organic framework PCN-777 with or without modification with polymers like polyethyleneimine (PEI) and polystyrene (PS). The polymers were applied in this study in order to reduce the pore size of PCN-777 (P777) and to introduce basic sites when PEI was used. PCN-777 s loaded with both the PEI and PS were effective in CO₂ adsorption because of reduced pore size; and PEI@PCN-777 s were highly effective in CO₂ capture owing to basic sites on PEI. For example, the best adsorbent (among the studied PCN-777-based adsorbents), PEI(20%)@P777, showed around 2.3 and 5.7 times of adsorption capacity (at 0.15 atm) and selectivity (CO₂/N₂), respectively, as much as those of the pristine P777. Moreover, this MOF is recyclable and has the recommended heat of adsorption when adsorbed CO₂ is not much. Therefore, it might be suggested that mesoporous MOFs, not suitable for CO₂ capture under low pressure (because of too big pore), can be modified facilely for effective CO₂ adsorption (especially under low pressure of 1 atm or less) by loading polymers with basicity onto the mesoporous MOFs.

从废气中选择性捕集CO ₂对于我们的可持续发展（包括缓解全球变暖）非常重要。在这里，我们研究了通过使用介孔Zr基金属有机骨架PCN-777，在有或没有用聚乙烯亚胺（PEI）和聚苯乙烯（PS）进行改性的情况下，在低压下对CO ₂和N _2的吸附。为了减少PCN-777（P777）的孔径并在使用PEI时引入碱性位点，在本研究中使用了该聚合物。装有PEI和PS的PCN-777由于孔径减小而对CO _2的吸附有效。和PEI @ PCN-777在CO ₂方面非常有效由于PEI上的基本站点而被捕获。例如，最佳吸附剂（在所研究的基于PCN-777的吸附剂中）PEI（20％）@ P777显示出约2.3倍和5.7倍的吸附容量（在0.15 atm时）和选择性（CO ₂ / N ₂），分别与原始的P777一样多。而且，该MOF是可回收的，并且在吸附的CO ₂不多时具有推荐的吸附热。因此，可能建议通过加载聚合物可以对不适合在低压（由于大孔）下捕获CO _2的中孔MOF进行改性，以有效吸附CO ₂（尤其是在1 atm或更低的低压下）。具有基本的介孔MOF。