Ultrafast Carbon Dioxide Sorption Kinetics Using Morphology-Controllable Lithium Zirconate

• Published in: ACS applied materials & interfaces Vol. 11; no. 1; pp. 691 - 698
• Main Authors: Liu, Fa-Qian, Li, Guo-Hua, Luo, Shu-Wen, Li, Wei-Hua, Huang, Zhao-Ge, Li, Wei, Su, Feng, Li, Chao-Qin, Ding, Zhen-Bo, Jiang, Qinglong
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 09.01.2019
• Subjects: CO2 capture; morphology-controllable synthesis; lithium zirconate; sorption kinetics; double-exponential model
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.8b16463

It was reported that the main obstacle of Li2ZrO3 as high-temperature CO2 absorbents is the very slow CO2 sorption kinetics, which are ascribed to the gradual formation of compact zirconia and carbonate shells along with inner unreacted lithium zirconate cores; accordingly, the “sticky” Li+ and O2– ions have to travel a long distance through the solid shells by diffusion. We report here that three-dimensional interconnected nanoporous Li2ZrO3 exhibiting ultrafast kinetics is promising for CO2 sorption. Specifically, nanoporous Li2ZrO3 (LZ-NP) exhibited a rapid sorption rate of 10.28 wt %/min with an uptake of 27 wt % of CO2. Typically, the k 1 values of LZ-NP (kinetic parameters extracted from sorption kinetics) were nearly 1 order of magnitude higher than the previously reported conventional Li2ZrO3 reaction systems. Its sorption capacity of 25 wt % within ∼4 min is 2 orders of magnitude faster than those obtained using spherical Li2ZrO3 powders. Furthermore, nanoporous Li2ZrO3 exhibited good stability over 60 absorption–desorption cycles, showing its potential for practical CO2 capture applications. CO2 adsorption isotherms for Li2ZrO3 absorbents were successfully modeled using a double-exponential equation at various CO2 partial pressures.