Multi-Scale Computer-Aided Design of Covalent Organic Frameworks for CO₂ Capture in Wet Flue Gas

Abstract

Discovery of remarkable porous materials for CO2 capture from wet flue gas is of great significance to reduce the CO2 emissions, but elucidating the most critical structure features for boosting CO2 capture capabilities remains a great challenge. Here, machine-learning-assisted Monte Carlo computational screening on 516 experimental covalent organic frameworks (COFs) identifies the superior secondary building units (SBUs) for wet flue gas separation using COFs, which are tetraphenylporphyrin units for boosting CO2 adsorption uptake and functional groups for boosting CO2/N2 selectivity. Accordingly, 1233 COFs are assembled using the identified superior SBUs. Density functional theory calculation analysis on frontier orbitals, electrostatic potential, and binding energy reveals the influencing mechanism of the SBUs on the wet flue gas separation performance. The “electron-donating-induced vdW interaction” effect is discovered to construct the better-performing COFs, which can achieve high CO2 uptake of 4.4 mmol·g–1 with CO2/N2 selectivity of 104.8. Meanwhile, the “electron-withdrawing-induced vdW + electrostatic coupling interaction” effect is unearthed to construct the better-performing COFs with superior CO2/N2 selectivity, which can reach 277.6 with CO2 uptake of 2.2 mmol·g–1; in this case, H2O plays a positive contribution in improving CO2/N2 selectivity. This work provides useful guidelines for designing optimized two-dimensional-COF adsorbents for wet flue gas separation.

Construction of Covalent Organic Frameworks via Multicomponent Reactions

“…Function-oriented material synthesis strategies start with the prospective function rather than structure, harnessing the brainpower of chemists and the power of computers (such as data mining and machine learning) to create new structures with the desired functions . In view of their well-defined structures, COFs offer a unique opportunity to establish structure–property correlations and develop purposeful structural design for obtaining the desired functionality prior to material synthesis . MCRs are an excellent choice for achieving the function-oriented synthesis of COFs because of their potential to integrate three or more functional blocks capable of conferring unexpected properties and functions on COFs through synergistic interactions in addition to providing their functions independently.…”

Revolutionizing the structural design and determination of covalent–organic frameworks: principles, methods, and techniques

“…Modified with permission. 155 Copyright 2022, American Chemical Society. (e) High-performance COFs for heating, cooling and ice-making were identified through high-throughput computational screening based on large classical Monte Carlo simulations in ML.…”

Construction of N-Rich Aminal-Linked Porous Organic Polymers for Outstanding Precombustion CO2 Capture and H2 Purification: A Combined Experimental and Theoretical Study

“…. Typically used solid sorbents like zeolites and porous carbons did not fulfill all requirements due to their low working capacities and/or low CO 2 /H 2 selectivity. − Various porous materials with a good CO 2 adsorption capacity at low pressure as well as high pressure, such as metal organic frameworks, − porous organic polymers, − and covalent organic frameworks, − have been used. However, to the best of our knowledge, most of these porous materials were studied for postcombustion CO 2 , and only few studies were reported on precombustion CO 2 capture, i.e., high-pressure CO 2 uptake. , The stored CO 2 can be reduced to value-added chemicals like methanol, formic acid, and so forth through high-pressure hydrogenation …”