Department of Materials Science and Engineering, Kyoto University, Sakyo, Kyoto, 606-8501, Japan.
Phys Chem Chem Phys. 2014 Mar 14;16(10):4814-22. doi: 10.1039/c4cp00021h.
Both classical and quantum mechanical simulation techniques have been applied to investigate the incorporation, migration and potential binding of protonic defects in bulk yttria-stabilised zirconia (YSZ). The calculated redox reaction energies are found to be high, although the reduction energies are lower than those of bulk cubic ZrO2 and are shown to decrease further with increasing Y content. The hydration energies for YSZ are also lower than the values calculated for bulk ZrO2 and are found to be lowest when the oxygen ion is in close proximity to at least one Y ion. Strong binding (proton trapping) energies are observed between the protons and additional acceptor dopants including Sc, Yb and Gd. These energies are found to vary significantly depending on local configuration and again are generally lower than the values for ZrO2. Density functional theory (DFT) calculations are used to determine energy barriers for proton transfers via neighbouring oxygen ions (Grötthuss-type mechanism). Energy barriers of 0.32-0.42 eV are obtained for the pathways with the closest O-O interatomic distances and are found to be very comparable to well-established proton conducting materials.
已应用经典和量子力学模拟技术来研究质子缺陷在体相氧化钇稳定氧化锆（YSZ）中的掺入、迁移和潜在结合。计算出的氧化还原反应能垒很高，尽管还原能垒低于体相立方氧化锆，但随着 Y 含量的增加而进一步降低。YSZ 的水合能也低于体相氧化锆的计算值，并且当氧离子与至少一个 Y 离子接近时，水合能最低。质子与包括 Sc、Yb 和 Gd 在内的额外受主掺杂剂之间观察到强结合（质子捕获）能。这些能量取决于局部构型，并且通常低于氧化锆的值。密度泛函理论（DFT）计算用于确定通过相邻氧离子的质子转移能垒（Grötthuss 型机制）。对于具有最近 O-O 原子间距离的途径，获得了 0.32-0.42 eV 的能垒，并且与成熟的质子导电材料非常可比。
