New Catalytic and Sorption Bifunctional Li₆CoO₄ Material for Carbon Monoxide Oxidation and Subsequent Chemisorption

Abstract

Hexalithium cobaltate (Li6CoO4) was synthesized by a solid-state reaction and evaluated as a possible simultaneous CO oxidant and CO2 chemisorbent, namely, as a bifunctional material. The analysis of this process was performed using catalytic and thermogravimetric techniques, under dynamic and isothermal conditions in both cases. After this, the isothermal sample products were characterized by X-ray diffraction (XRD) and Raman spectroscopy. Catalytic and thermogravimetric experiments were performed in the presence and absence of oxygen to further analyze the reaction paths performed during the double CO oxidation and chemisorption process. The thermogravimetric analysis evidenced the carbonation process through lithium carbonate formation, while catalytic results clearly showed that Li6CoO4 was able to perform the CO oxidation even if the CO2 produced was not completely chemically trapped. Moreover, different compounds were identified on the isothermal sample products (determined by XRD) depending on the oxygen provision, indicating variations in the reaction paths. Since lithium cobaltate (LiCoO2) was obtained as an isothermal product during the experiments in the presence of oxygen, it was synthesized and analyzed as a possible catalyst and sorbent bifunctional material. LiCoO2 showed a high catalytic behavior toward CO oxidation, although its CO2 chemisorption capacity was not as high as expected, at least under the same physicochemical conditions used for Li6CoO4. Based on these results, it can be established that Li6CoO4 produces LiCoO2 as a secondary phase during the CO oxidation and carbonation process. Thus, the real CO2 capture on Li6CoO4 can be established as 5/6 of the lithium content of the ceramic.

Na0.6Co3O4- La/Pr co-Doped Ceria as Semiconductor-Ionic Heterostructure Material for Fuel Cell Application

“…9 Two additional peaks of 8LCP-2NCO material at 1350 cm −1 and 1600 cm −1 observed after the fuel cell testing which were also due to the pollution caused by carbon dioxide in air. 26 As shown in Fig. 5d, the surface composition of 8LCP-2NCO composite before and after the testing was studied by FTIR analysis.…”

Enhanced carbon dioxide capture performance of natural mineral vermiculite‐derived lithium silicate with Na doping

“…When the temperature is increased from 450 to 500°C, the adsorption capacity increases to 22.55 wt% with only 1.83 wt% increment. This effect is attributed to the formation of the Li 2 CO 3 shell, 1 and the external shell inhibits the CO 2 bulk chemisorption. Besides, the diffusion processes are not fully activated in this temperature range.…”

“…Carbon dioxide (CO 2 ) has already been regarded as the dominating anthropogenic greenhouse gas and the chief culprit in global climate change, and thus the development of an effective CO 2 capture and separation/sequestration (CCS) is of paramount significance for the ecological system. [1][2][3] High-temperature solid CO 2 adsorbents have great potential to mitigate the concentration of atmospheric CO 2 in the postcombustion capture process, mainly due to their low energy penalty and flexible operability. [4][5][6][7] Moreover, high-temperature CO 2 captors are crucial for the sorption enhanced steam methane reforming (SESMR) process.…”

Scrutinizing the CO Chemical Capture Path in Li2MnO3 Samples with Different Microstructural Properties

“…Within this environmental context, the CO separation process possesses high interest during hydrogen (H 2 ) production, as most of this clean energetic vector is produced as gas mixtures containing both H 2 and CO coming from different catalytic processes. − Based on that, in the past years, different materials used as CO 2 chemisorbents − have been proposed as possible CO chemical captors. − In most of these cases, CO chemisorption implies an initial oxidation induced by an oxygen (O 2 ) flow present in the gas mixture. Nevertheless, a few of these materials have shown their ability to chemically trap CO even in the O 2 absence, i.e.…”