Hydroxylamine-Anchored Covalent Aromatic Polymer for CO₂ Adsorption and Fixation into Cyclic Carbonates

Abstract

Hydroxylamine-anchored covalent aromatic polymer (CAP-DAP) was synthesized from p-terphenyl and 1,3,5benzene tricarbonyl chloride, followed by subsequent functionalization with 1,3-diamino-2-propanol for CO 2 capture and metalfree catalysis in CO 2 −epoxide cycloaddition reactions. The novel CAP-DAP material was characterized using various analytical techniques. It showed very good CO 2 adsorption capacity of 153 mg/g along with a high (CO 2 /N 2 ) selectivity of 86 at 273 K/1 bar, in contrast to bare CAP, which exhibited moderate CO 2 adsorption of 136 mg/g with a CO 2 /N 2 selectivity of 47. CAP-DAP also displayed high catalytic activity for CO 2 −epoxide cycloaddition reactions under mild and solvent-free conditions. The synergistic effect between metal-free CAP-DAP and tetrabutylammonium bromide (n-Bu 4 NBr) enabled a high epoxide conversion of 98% coupled with an excellent product selectivity of 99% at 60 °C, 1 bar CO 2 , and a reaction time of 12 h. Faster reaction kinetics with reaction times <6 h was possible at 80 °C. The catalyst also showed excellent reusability and no leaching of active species was observed from the spent catalyst. Based on experimental results, a plausible reaction mechanism for CO 2 − epoxide cycloaddition reaction over CAP-DAP catalyst has been proposed.

Recent developments in organocatalysed transformations of epoxides and carbon dioxide into cyclic carbonates

“…In 2018, Ahn et al developed an amino alcohol-containing covalent aromatic polymer 61 for the capture and catalytic conversion of carbon dioxide (Scheme 35). 190 Although the surface area of 61 was lower than that of the corresponding covalent aromatic polymer, which did not contain amino-alcohol functional groups, the carbon dioxide capture capacity of 61 was higher: 153 mg g -1 versus 136 mg g -1 at 273 K, which indicated the important role of the aminoalcohol groups. In the presence of quaternary ammonium salts such as tetrabutylammonium bromide (2 mol%), polymer 61 converted terminal epoxides into cyclic carbonates in 82-96% yields, at 60 o C and 1 bar of carbon dioxide after 12 h. The yield reported for the internal epoxide cyclohexene oxide, however, was only 13%.…”

Ionic‐Liquid‐Functionalized UiO‐66 Framework: An Experimental and Theoretical Study on the Cycloaddition of CO2 and Epoxides

“…[1] Efficient catalytic technologies that utilize CO 2 as carbon feedstock would be favorable for mitigating globalw arming. [4][5][6][7][8][9][10] Ap rominent CO 2 fixation method is the atom-efficient cycloadditiono fe poxides to CO 2 to produce industrially and economically importantf ive-membered cyclic carbonates. [4][5][6][7][8][9][10] Ap rominent CO 2 fixation method is the atom-efficient cycloadditiono fe poxides to CO 2 to produce industrially and economically importantf ive-membered cyclic carbonates.…”

“…[2,3] Compared to carbon capture and storage( CCS) techniques, carbon capturea nd utilization (CCU) techniques are more attractive, ast he captured CO 2 can be effectively converted to various valuable productss uch as urethanes, formic acid, dimethyl carbonate, and cyclic carbonates. [4][5][6][7][8][9][10] Ap rominent CO 2 fixation method is the atom-efficient cycloadditiono fe poxides to CO 2 to produce industrially and economically importantf ive-membered cyclic carbonates. [11][12][13][14][15][16][17][18][19][20] Cyclic carbonates are highly stable compounds; thus, long-term sequestration of CO 2 is possible.…”

The Application of Biomass-Based Catalytic Materials in the Synthesis of Cyclic Carbonates from CO2 and Epoxides

“…Thus, the resulting cyclic carbonates are obtained with a 100% atom economy. Several representative catalysts, including ionic liquids [ 7 , 8 , 9 , 10 ], metal complexes [ 11 , 12 , 13 ], metal oxides [ 14 , 15 ], porous carbon [ 16 , 17 , 18 ], porous organic polymers [ 19 , 20 , 21 , 22 ], metal-organic frameworks (MOFs) [ 23 , 24 , 25 ], covalent organic frameworks (COFs) [ 26 , 27 , 28 ], and biomass-based catalysts [ 29 , 30 , 31 ], have been developed for the synthesis of cyclic carbonates from CO 2 and epoxides. In particular, biomasses including cellulose, lignin, and hemicellulose, among others, are the most accessible and renewable resources with abundant hydrogen bonds, which can be used as catalyst materials for CO 2 conversion.…”