Chemical similarity of dialkyl carbonates and carbon dioxide opens an avenue for novel greenhouse gas scavengers: cheap recycling and low volatility via experiments and simulations

• Published in: Physical chemistry chemical physics : PCCP 2023-03, Vol.25 (13), p.9320-9335
• Main Authors: Chaban, Vitaly V, Andreeva, Nadezhda A, Bernard, Franciele L, M Dos Santos, Leonardo, Einloft, Sandra
• Format: Article
• Language: English
• Subjects: Binding energy; Carbon dioxide; Carbonates; Chains; Chemical fingerprinting; Greenhouse effect; Greenhouse gases; Oxidation; Phase transitions; Recyclability; Robustness (mathematics); Scavengers; Sorbents; Sorption
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/d2cp06089b

Global warming linked to the industrial emissions of greenhouse gases may be the end of mankind unless it is adequately and timely handled. To prevent irreversible changes to the climate of the Earth, numerous research groups are striving to develop robust CO sorbents. Dialkyl carbonates (DACs) and CO exhibit obvious chemical similarities in their structure and properties. The degrees of oxidation of all atoms composing DACs and CO are identical resulting in very similar nucleophilicities and electrophilicities of all interaction centers. While both compounds possess relatively high partial atomic charges on their polar moieties, the molecular geometries prevent tight binding of the head groups. The computed DAC-DAC binding energies are ∼40 kJ mol , whereas the effect of the alkyl chain length is marginal. The phase transition points and shear viscosities of DACs are very low. We herein hypothesize and numerically rationalize that DACs represent noteworthy physical sorbents for CO thanks to the similar sorbent-CO and sorbent-sorbent interaction energies. By reporting -derived sorption thermodynamics at various conditions, spectral and structural properties, and experimentally derived CO capacities and recyclabilities, we highlight the mutual affinity of DACs and CO . Indeed, the experimentally determined CO sorption capacity of 0.88 mol% (diethyl carbonate) at 278.15 K and 30 bar is competitive. The unprecedentedly low DAC-CO binding energies, ∼14 kJ mol , suggest a low-cost desorption process and outstanding recyclability of the sorbent. We also note that DACs possessing long alkyl chains (butyl, hexyl, octyl) exhibit negligible volatilities, while preserving the liquid aggregate state over a practically important temperature range. The reported results may foster the development of a new class of CO scavengers with possibly quite peculiar characteristics.