Adsorption behavior of carbonic acid on γ‐dicalcium silicate surface from molecular simulations

• Published in: Journal of the American Ceramic Society
• Main Authors: Zhao, Meicheng, Lu, Linnu, Tao, Yong, He, Yongjia, Wang, Fazhou, Zhang, Wenqin, Hu, Shuguang
• Other Authors: National Natural Science Foundation of China, China Scholarship Council
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2021
• Subjects: Materials Chemistry; Ceramics and Composites; Carbonic acid
• Online Access: http://dx.doi.org/10.1111/jace.18081; https://onlinelibrary.wiley.com/doi/pdf/10.1111/jace.18081; https://onlinelibrary.wiley.com/doi/full-xml/10.1111/jace.18081

Abstract This paper aims to investigate the adsorption of carbonic acid and water molecules on the (010) surface of γ‐dicalcium silicate (γ‐C 2 S) at an atomic scale using density functional theory (DFT) and ab initio molecular dynamics. It provides novel insights into the mechanism of carbonation on the surface of γ‐C 2 S. The electrons transfer and interfacial reactions between the carbonic acid (H 2 CO 3 ) molecule and the γ‐C 2 S surface are characterized by adsorption configuration, bond order, electron density difference, and partial density of states. There exist strong interactions between H 2 CO 3 and γ‐C 2 S surface, including two types of chemical adsorption and one type of physical adsorption. This work confirms that water in the carbonation of γ‐C 2 S is to react with CO 2 to provide the reactants, and protons transfer of the carbonic acid molecule plays a crucial role in the carbonation process. The adsorption of the carbonic acid molecule is more favorable with respect to that of the water molecule, which may be the initial step of the carbonization of γ‐C 2 S.