Functional Group Adsorption on Calcite: I. Oxygen Containing and Nonpolar Organic Molecules
Functional Group Adsorption on Calcite: I. Oxygen Containing and Nonpolar Organic Molecules
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DOI：
10.1021/acs.jpcc.6b01349
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发表时间：
2016-08-04
影响因子：
3.7
通讯作者：
Stipp, S. L. S.
中科院分区：
文献类型：
--
作者：
Ataman, E.;Andersson, M. P.;Stipp, S. L. S.
对方解石结晶的极大兴趣促使了许多关于有机分子吸附的研究。然而，每项研究仅探索了少数化合物，使用不同的方法和条件，因此很难将结果组合成描述基本机制的通用模型。我们的目标是通过探索常见官能团如何与方解石相互作用以及各种侧基和氢对吸附的影响，根据一系列有机化合物的行为开发综合吸附模型。我们使用密度泛函理论和半经验色散校正 (DFT-D2) 来确定方解石 {10.4} 对非极性分子（苯、乙烷和二氧化碳）和含氧极性分子（水、甲醇、乙醇、苯酚、甲酸、乙酸、丙酸、苯甲酸、甲醛、乙醛、丙醛、苯甲醛、二甲醚、丙酮和呋喃）的吸附能。根据吸附能，在过渡态理论近似内，我们推导出每个分子的解吸温度。然后，我们使用 X 射线光电子能谱 (XPS) 确定了四种代表性分子的解吸温度，并将实验结果与预测结果进行了比较。羧酸 (R-COOH) 比水和醇 (ROH) 吸附更强，而水和醇 (ROH) 又比醛 (R-CHO) 吸附更强。氢原子或侧基的连接会改变羟基和醛官能团的吸附行为，但不会显着影响羧基官能团。
Considerable interest in calcite crystallization has prompted many studies on organic molecule adsorption. However, each study has explored only a few compounds, using different methods and conditions, so it is difficult to combine the results into a general model that describes the fundamental mechanisms. Our goal was to develop a comprehensive adsorption model from the behavior of a range of organic compounds by exploring how common functional groups interact with calcite and the effects of various side groups and hydrogen on adsorption. We used density functional theory, with semiempirical dispersion corrections (DFT-D2), to determine adsorption energy on calcite {10.4} for nonpolar (benzene, ethane, and carbon dioxide) and oxygen containing polar molecules (water, methanol, ethanol, phenol, formic acid, acetic acid, propanoic acid, benzoic acid, formaldehyde, acetaldehyde, propionaldehyde, benzaldehyde, dimethyl ether, acetone, and furan). From the adsorption energies, within the transition state theory approximation, we derived desorption temperature for each molecule. Then we used X-ray photoelectron spectroscopy (XPS) to determine the desorption temperature for four representative molecules and compared the experimental results with those predicted. Carboxylic acids (R-COOH) adsorb more strongly than water and alcohols (ROH), which in turn adsorb more strongly than the aldehydes (R-CHO). Attachment of a hydrogen atom or a side group changes adsorption behavior for hydroxyl and aldehyde functional groups but does not affect the carboxyl functional group significantly.