Calculation of interaction of AlCl, AlCl₂ and AlCl₃ on Al₄C₃ (001) Al₄CO₄ (001) and Al₂CO (001) planes

DUAN Shao-fei(段少飞)^{1, 2}, CHEN Xiu-min(陈秀敏)^{1, 2}, YANG Bin(杨斌)^{1, 2}, YU Qing-chun(郁青春)^{1, 2}, XU Bao-qiang(徐宝强)^1,2,  LIU Da-chun(刘大春)^1,2

(1. National Engineering Laboratory for Vacuum Metallurgy
(Kunming University of Science and Technology), Kunming 650093, China;
2. Yunnan Provincial Key Laboratory of Nonferrous Vacuum Metallurgy, Kunming 650093, China)

Abstract:To make sure the intermediate products of the carbothermic reduction of Al₂O₃ process, such as Al₄CO₄, Al₂CO and Al₄C₃, and the interaction of AlCl, AlCl₂, AlCl₃ with Al₄CO₄, Al₂CO and Al₄C₃, respectively, thermodynamic analyses were used to study the chloride reaction production of them under the vacuum situation. The stable structures and electronic properties of AlCl, AlCl₂ and AlCl₃ adsorbed on Al₄CO₄, Al₂CO and Al₄C₃ were calculated by first-principles calculations by the CASTEP module in the Materials Studio program. The results show that the AlCl₃ and AlCl₂ molecules have decomposed on the plane of Al₄C₃ (001), while there are no obvious decomposition of AlCl₃ and AlCl₂ on Al₄CO₄ (001) and Al₂CO (001) planes. The adsorption of AlCl on the Al₄CO₄ (001) and Al₂CO (001) planes is stronger than that on the Al₄C₃(001) plane. The interaction strength of AlCl₃, as well as AlCl₂, with Al₄CO₄, Al₂CO and Al₄C₃ is in the sequence of Al₄CO₄<Al₂CO<Al₄C₃, while the interaction strength of AlCl with Al₄CO₄, Al₂CO and Al₄C₃ is in the sequence of Al₄CO₄>Al₂CO>Al₄C₃.

Key words:Ab initio; chloride reaction; carbothermic reduction; Al₄C₃; Al₄CO₄; Al₂CO