Evaluation of Aliphatic Alcohols for CO2 Capture Using the Characteristic Carbonate Frequency.

Autor: Delibas B; University of Southern California, Chemistry, UNITED STATES OF AMERICA., Cotton D; University of Southern California, Chemistry, UNITED STATES OF AMERICA., Sudhakaran KP; University of Southern California, Chemistry, UNITED STATES OF AMERICA., Dawlaty JM; University of Southern California Health Sciences Center, Chemistry, 920 Bloom Walk, 90089, Los Angeles, UNITED STATES OF AMERICA.
Jazyk: angličtina
Zdroj: ChemSusChem [ChemSusChem] 2024 Dec 05, pp. e202402288. Date of Electronic Publication: 2024 Dec 05.
DOI: 10.1002/cssc.202402288
Abstrakt: Control over CO2 capture and utilization are important scientific and technological challenges. Although a variety of amine absorbents are used for capture, releasing the captured CO2 is often difficult and limits their recyclability. Therefore, it is crucial to control the strength of the CO2 bond with the absorbent. Furthermore, it is desirable to use a method that can conveniently report the strength of this bond. This motivates exploring adducts of CO2 with alcohols in the presence of a base, using vibrational spectroscopy to report on the bond strength. Although reactions of alcohols with CO2 to form alkyl carbonates are known, a systematic study of these adducts has not been conducted. Here we show formation of alkyl carbonates by a series of alcohols spanning the pKa range 9.5 to 16.8. We show experimental and computational results for the frequency of the characteristic asymmetric stretch of the carbonate and demonstrate that it correlates inversely with the pKa of the alcohol. Based on computations of the bond lengths and previous work, we propose that this frequency also correlates inversely with the adduct strength. This work extends the scope of CO2 capture reagents and inspires further research in tuning alcohols as reversible absorbents.
(© 2024 Wiley‐VCH GmbH.)
Databáze: MEDLINE
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