Wen Hui-Min, Liao Caijun, Li Libo, Alsalme Ali, Alothman Zeid, Krishna Rajamani, Wu Hui, Zhou Wei, Hu Jun, Chen Banglin
College of Chemical Engineering, Zhejiang University of Technology, Chaowang Road #18, Hangzhou 310014, Zhejiang, China.
Department of Chemistry, University of Texas at San Antonio, One UTSA Circle, San Antonio, Texas 78249-0698, USA.
J Mater Chem A Mater. 2019 Jan;7(7). doi: 10.1039/C8TA11596F.
Capturing carbon dioxide (CO) from flue gases with porous materials has been considered as a viable alternative technology to replace traditional liquid amine adsorbents. A large number of microporous metal-organic frameworks (MOFs) have been developed as CO-capturing materials. However, it is challenging to target materials with both extremely high CO capture capacity and gas selectivity (socalled trade-off) along with moderate regeneration energy. Herein, we developed a novel porous material, [Cu(dpt)(SiF)] (termed as UTSA-120; dpt = 3,6-di(4-pyridyl)-1,2,4,5-tetrazine), which is isoreticular to the net of SIFSIX-2-Cu-i. This material exhibits simultaneously high CO capture capacity (3.56 mmol g at 0.15 bar and 296 K) and CO/N selectivity (~600), both of which are superior to those of SIFSIX-2-Cu-i and most other MOFs reported. Neutron powder diffraction experiments reveal that the exceptional CO capture capacity at the low-pressure region and the moderate heat of CO adsorption can be attributed to the suitable pore size and dual functionalities (SiF6 and tetrazine) which not only interact with CO molecules but also enable the dense packing of CO molecules within the framework. Simulated and actual breakthrough experiments demonstrate that UTSA-120a can efficiently capture CO gas from the CO/N (15/85, v/v) and CO/CH (50/50) gas mixtures under ambient conditions.
用多孔材料从烟道气中捕获二氧化碳（CO₂）被认为是一种可行的替代技术，可取代传统的液体胺吸附剂。大量的微孔金属有机框架（MOF）已被开发用作CO₂捕获材料。然而，要找到同时具有极高的CO₂捕获能力、气体选择性（即所谓的权衡）以及适度再生能量的材料具有挑战性。在此，我们开发了一种新型多孔材料[Cu(dpt)(SiF₆)]（称为UTSA-120；dpt = 3,6-二（4-吡啶基）-1,2,4,5-四嗪），它与SIFSIX-2-Cu-i的网络同构。这种材料同时表现出高的CO₂捕获能力（在0.15 bar和296 K下为3.56 mmol g⁻¹）和CO₂/N₂选择性（约600），这两者均优于SIFSIX-2-Cu-i和报道的大多数其他MOF。中子粉末衍射实验表明，在低压区域的出色CO₂捕获能力和适度的CO₂吸附热可归因于合适的孔径和双重功能（SiF₆和四嗪），它们不仅与CO₂分子相互作用，还能使CO₂分子在框架内紧密堆积。模拟和实际的突破实验表明，UTSA-120a在环境条件下能有效地从CO₂/N₂（15/85，v/v）和CO₂/CH₄（50/50）气体混合物中捕获CO₂气体。
