Synthesis of Li4+xSi1−xFexO4 solid solution by dry ball milling and its highly efficient CO2 chemisorption in a wide temperature range and low CO2 concentrations

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Materials for energy and sustainability, 2019-01, Vol.7 (8), p.4153-4164
• Main Authors: Lara-García, Hugo A, Ovalle-Encinia, Oscar, Ortiz-Landeros, José, Lima, Enrique, Pfeiffer, Heriberto
• Format: Article
• Language: English
• Subjects: Ball milling; Carbon dioxide; Carbon sequestration; Ceramics industry; Chemisorption; Industrial applications; Iron; Kinetics; Operating temperature; Organic chemistry; Partial pressure; Redox properties; Solid solutions; Sorption; Synthesis; Temperature; Temperature dependence; Temperature effects
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/c8ta12359d

To be considered a good CO2 capture material for industrial applications, alkaline ceramics have to present several properties such as fast sorption and desorption kinetics, large sorption capacities, regenerability and stability, and a wide operating temperature range. In this sense, Li4SiO4 fulfills some of these features, although it has some kinetic disadvantages at temperatures lower than 500 °C and under low CO2 partial pressures. Herein, we show an easy an efficient way to synthesize a Fe-containing Li4SiO4 solid solution (Li4+xSi1−xFexO4, with x ≤ 0.5); by a dry ball milling synthesis, with high CO2 capture capacities. A synergic effect, between the microstructural features given by the proposed synthesis method and the iron content, improves the CO2 capture exhibited by the material in different ways: (1) Li4+xSi1−xFexO4 solid solution samples are able to trap large amounts of CO2 between 200 and 650 °C. At 200 °C, the solid solution chemisorbs 11 wt% of CO2, the largest amount of CO2 captured reported so far in the literature at this temperature; (2) iron containing samples diminish the CO2 capture dependence on temperature; (3) CO2 capture was considerably improved under low partial pressures of CO2 and (4) iron redox properties enhanced the CO2 capture, by using a low partial pressure of O2.