First‐principles study of the adsorption mechanism of SO2 and CF4 on the α‐Al2O3 (0001) surface. Issue 5 (22nd October 2020)

• Record Type: Journal Article
• Authors: Yu, Xinyan; Zhang, Hongliang; Li, Jie; Guo, Hui; Wang, Jingkun; Wang, Jiacheng; Long, Mengqiu
• Is Part Of: International journal of quantum chemistry. Volume 121:Issue 5(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-10-22
• Subjects: computational chemistry -- density of states -- first principles -- gas adsorption -- molecules; Quantum chemistry -- Periodicals; 541.28
• DOI: 10.1002/qua.26507
• Languages: English
• ISSNs: 0020-7608

Abstract

Abstract: Due to greenhouse gas emission restrictions and environmental protection requirements, the treatment of SO2 and Perfluorinated compound gas has become a problem in the aluminum electrolysis industry. Based on the density functional theory, the adsorption mechanisms of SO2 and CF4 on the surface of clean α‐Al2 O3 (0001) were studied. Using projected augmented wave/Perdew‐Burke‐Ernzerhof for calculation, it can be found that SO2 is adsorbed to form an AlO1 SO2 structure, and the most stable adsorption energy is −1.52 eV. The adsorption of SO2 is mainly due to the action of π‐p orbitals and the partial contribution of sp 2 hybrid orbitals and s orbitals. The most stable adsorption energy of CF4 is −0.38 eV, and it is difficult to transfer charge on the surface. Overall, SO2 is chemisorbed on the clean surface, while CF4 is physisorbed, and their coadsorption with H2 O is disadvantageous to the adsorption reaction. These results are very important for understanding the adsorption mechanism of CF4 and SO2 on alumina. Abstract : First principle calculations of the adsorption property and reaction mechanism of SO2 and CF4 on alumina are presented. According to the results of adsorption energy, structural relaxation, and charge distribution, the electron transfer of CF4 on alumina is less than that of SO2 . The alumina surface with preadsorbed H2 O is not conducive to adsorption, and at high concentration SO2 will desorb. The results of this paper want to have important guiding significance for the industrial treatment of SO2 and CF4 .