The regeneration mechanisms of sulfurized α-Fe2O3 surfaces under O2 atmosphere:A density functional theory study
The regeneration mechanisms of sulfurized α-Fe2O3 desulfurization sorbent under O2 atmosphere are systematically studied by density functional theory(DFT)slab calculation.The regeneration pathways are proposed for two sulfurized surfaces,“S-contained surface” and “S-adsorbed surface”,which are derived from the substitution of surface O atom by S atom and the adsorption of S atom on the surface Fe atom,respectively.Our results show that two competitive regeneration pathways exist on each sulfurized surface.For the regeneration on the S-contained surface and the S-adsorbed surface,the rate-determining step is the dissociation of O2 with the energy barriers of 136.7 and 227.3 kJ·mol-1,respectively,suggesting that the regeneration on the Scontained surface is easier than that on the S-adsorbed surface.Then,the O vacancy on the α-Fe2O3(0001)surface can be repaired under O2 atmosphere,and the reparation mechanism demonstrates that the dissociation of O2 on the O-vacancy α-Fe2O3(0001)surface only needs to overcome a lower energy barrier of 49.8 kJ·mol-1 than those(136.7 and 227.3 kJ·mol-1)on two sulfurized surfaces.As a result,the presence of O vacancy on the α-Fe2O3(0001)surface can accelerate the dissociation of O2,which is favorable to the regeneration of sulfurized surfaces.
Regeneration Sulfurized surfaces α-Fe2O3(0001) surface Density functional theory
Baojun Wang Jiajia Song Xiaoqi Niu Lixia Ling
Key Laboratory of Coal Science and Technology(Taiyuan University of Technology),Ministry of Educatio Key Laboratory of Coal Science and Technology(Taiyuan University of Technology),Ministry of Educatio Research Institute of Special Chemicals,Taiyuan University of Technology,Taiyuan 030024 Shanxi,PR Ch
国内会议
大连
英文
665-677
2016-09-24（万方平台首次上网日期，不代表论文的发表时间）