Post-synthetic functionalization or modification has been regarded as a promising strategy to treat surfaces of adsorbents for their applications in targeted adsorption and separation processes. In this work, a novel microporous adsorbent for carbon capturing was developed via functionalization of zeolitic imidazolate frame-work-91 (ZIF-91) to generate a hard/hard (metal-oxygen) structure named as lithium-modified ZIF-91 (ZIF-91-OLi compound). To this purpose, the ZIF-91 compound as an intermediate product was achieved by reduction of ZIF-90 in the presence of NaBH₄ as a good reducing agent. Afterwards, acidic hydrogen atoms in the hydroxyl groups of ZIF-91 were exchanged with lithium cations via reaction of n-BuLi compound as an organo lithium agent through an appropriate procedure. In particular, the as-synthesized ZIF-91-OLi operated as an excellent electron-rich center for CO₂ adsorption through trapping the positive carbon centers in the CO₂ molecule. DFT calculations revealed that the presence of lithium over the surface of ZIF-91-OLi adsorbent plays an effective role in double enhancement of CO₂ storage via creating a strong negative charge center at the oxygen atoms of the imidazolate linker as a result of the lithium/hydrogen exchange system. Finally, the selectivity of CO₂/N₂ was investigated at different temperatures, revealing the ZIF-91-OLi as a selective adsorbent for industrial application.

合成后的功能化或修饰已被认为是处理吸附剂表面的有前途的策略，以用于其在目标吸附和分离过程中的应用。在这项工作中，通过对咪唑类沸石骨架91（ZIF-91）进行功能化，开发了一种新型的用于碳捕获的微孔吸附剂，以产生称为锂改性ZIF-91（ZIF）的硬/硬（金属-氧）结构-91-OLi化合物）。为此目的，通过在作为良好还原剂的NaBH ₄的存在下还原ZIF-90来获得作为中间产物的ZIF-91化合物。之后，ZIF-91羟基中的酸性氢原子通过n的反应与锂阳离子交换。通过适当的程序将-BuLi化合物用作有机锂试剂。特别地，通过将正碳中心捕获在CO ₂分子中，合成后的ZIF-91-OLi作为CO ₂吸附的优良富电子中心。DFT计算表明，在ZIF-91-OLi吸附剂表面存在锂，通过在锂上形成一个在咪唑酸酯连接基的氧原子上形成强负电荷中心，在CO ₂储存量的双重增强中起有效作用。/氢交换系统。最后，在不同温度下研究了CO ₂ / N ₂的选择性，揭示了ZIF-91-OLi作为工业应用的选择性吸附剂。