Avalos-Rendón Tatiana, Casa-Madrid Julio, Pfeiffer Heriberto
Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Circuito exterior s/n, Cd. Universitaria, México DF, Mexico.
J Phys Chem A. 2009 Jun 25;113(25):6919-23. doi: 10.1021/jp902501v.
Lithium aluminates (LiAlO(2) and Li(5)AlO(4)) were synthesized, characterized, and tested as possible CO(2) captors. LiAlO(2) did not seem to have good qualities for the CO(2) absorption. On the contrary, Li(5)AlO(4) showed excellent behavior as a possible CO(2) captor. Li(5)AlO(4) was thermally analyzed under a CO(2) flux dynamically and isothermically at different temperatures. These results clearly showed that Li(5)AlO(4) is able to absorb CO(2) in a wide temperature range (200-700 degrees C). Nevertheless, an important sintering effect was observed during the thermal treatment of the samples, which produced an atypical behavior during the CO(2) absorption at low temperatures. However, at high temperatures, once the lithium diffusion is activated, the sintering effect did not interfere with the CO(2) absorption. Eyring's model was used to determine the activation enthalpies of the CO(2) absorption (15.6 kJ/mol) and lithium diffusion (52.1 kJ/mol); the last one is the limiting process.
合成了铝酸锂（LiAlO₂ 和 Li₅AlO₄），对其进行了表征，并作为可能的 CO₂ 捕获剂进行了测试。LiAlO₂ 似乎不具备良好的 CO₂ 吸收性能。相反，Li₅AlO₄ 作为一种可能的 CO₂ 捕获剂表现出优异的性能。在不同温度下，对 Li₅AlO₄ 在 CO₂ 通量下进行了动态和等温热分析。这些结果清楚地表明，Li₅AlO₄ 能够在很宽的温度范围（200 - 700℃）内吸收 CO₂。然而，在样品热处理过程中观察到了重要的烧结效应，这在低温下的 CO₂ 吸收过程中产生了非典型行为。然而，在高温下，一旦锂扩散被激活，烧结效应就不会干扰 CO₂ 的吸收。使用艾林模型确定了 CO₂ 吸收（15.6 kJ/mol）和锂扩散（52.1 kJ/mol）的活化焓；后者是限制过程。
