Playing with covalent triazine framework tiles for improved CO₂ adsorption properties and catalytic performance

Abstract

The rational design and synthesis of covalent triazine frameworks (CTFs) from defined dicyano-aryl building blocks or their binary mixtures is of fundamental importance for a judicious tuning of the chemico-physical and morphological properties of this class of porous organic polymers. In fact, their gas adsorption capacity and their performance in a variety of catalytic transformations can be modulated through an appropriate selection of the building blocks. In this contribution, a set of five CTFs (CTF1–5) have been prepared under classical ionothermal conditions from single dicyano-aryl or heteroaryl systems. The as-prepared samples are highly micro-mesoporous and thermally stable materials featuring high specific surface area (up to 1860 m2·g−1) and N content (up to 29.1 wt %). All these features make them highly attractive samples for carbon capture and sequestration (CCS) applications. Indeed, selected polymers from this series rank among the CTFs with the highest CO2 uptake at ambient pressure reported so far in the literature (up to 5.23 and 3.83 mmol·g−1 at 273 and 298 K, respectively). Moreover, following our recent achievements in the field of steam- and oxygen-free dehydrogenation catalysis using CTFs as metal-free catalysts, the new samples with highest N contents have been scrutinized in the process to provide additional insights to their complex structure–activity relationship.

Assessing the Nature of Active Sites on Nanodiamonds as Metal-Free Catalysts for the EB-to-ST Direct Dehydrogenation Using a Catalytic Approach

“…The control of their surface chemical properties in terms of distinctive functional groups available, defective sites or light hetero-elements along with their ultimate morphology have unveiled the potentialities of these metal-free systems within a variety of catalytic applications. [7][8][9][10] They have successfully been scrutinized as valuable catalytic systems for a number of industrially relevant oxidation [11][12][13][14][15][16][17][18][19][20][21][22] and reduction [23][24][25][26][27][28][29][30][31] processes, including other challenging catalytic transformations. [32][33][34][35] Their high thermal stability, good electrical conductivity, porosity and tunable surface composition have boosted their exploitation in catalysis, often pointing out their superior activity and stability compared to traditional metal or metal oxide-based systems.…”

Effect of Building Block Transformation in Covalent Triazine‐Based Frameworks for Enhanced CO2 Uptake and Metal‐Free Heterogeneous Catalysis

“…In order to compare the observed CO 2 uptake properties with reported values, a few representative CTFs with different surface area, pore volume, nitrogen content and C/N ratio were included in Table (entries 5–11). On comparison, it can be stated that CO 2 capacities of the present new sets of CTF materials are higher than acac‐CTFs, DCI‐CTF, CTF‐1, and are comparable with many other CTFs with different heteroaromatic groups . However, they are lower than that observed in bipy‐CTF‐600 (5.58 mmol g −1 ), F‐DCBP‐CTF (5.98 mmol g −1 ), HAT‐CTF‐450/600 (6.3 mmol g −1 ), and triazole containing CTFs (7.65 mmol g −1 ) (entries 7–12).…”

Zwitterion π–conjugated nanoporous polymer based on guanidinium and β-ketoenol as a heterogeneous organo-catalyst for chemical fixation of CO2 into cyclic carbonates

“…Carbon dioxide (CO2) is one of the dominant anthropogenic greenhouse-gasses and the main culprit for global warming and climate change, hence CO2 chemistry (capture and conversion) has appealed worldwide as the most important and top priority for the scientific community [1][2][3][4][5][6][7]. Recently, the CO2 concentration increased to 415 ppm in the atmosphere and continue increasing.…”