Ab initio atomistic thermodynamics study on the sulfur tolerance mechanism of the oxygen-enriched yttria-stabilized zirconia surfaced

作者：Chu, Xingli; Zhang, Yanxing; Li, Shasha; Yang, Zongxian^*

来源：Surface Science, 2014, 622: 16-23.

DOI：10.1016/j.susc.2013.12.002

• Oxygen-enriched YSZ
• Sulfur poisoning
• Phase diagram
• Atomistic thermodynamics method
• Surface regeneration

The first-principles method based on density functional theory (DFT) is used to investigate the reaction mechanism for the adsorption of H2S on the oxygen-enriched yttria-stabilized zirconia (YSZ + O) (111) surface. It is found that the H2S dissociation processes have low energy barriers (<0.5 eV) and high exothermicities (2.5 eV), and the dissociative S atoms may result in the poisoning of the YSZ + O surface by forming the SO and the hyposulfite (SO22-) species with very strong bonds to the surface. In addition, using the ab initio atomistic thermodynamics method, the surface regeneration or de-sulfurization process of a sulfur-poisoned (i.e. sulfurcovered) YSZ + 0(111) surface is studied. According to the phase diagram, the adsorbed atomic sulfur can be oxidized to SO2 and removed from the YSZ + O surface by introducing oxidizing reagents, e.g. O-2 and H2O.

• 出版日期2014-4
• 单位河南师范大学