Fu Zhaoming, Wang Mingyang, Zuo Pengju, Yang Zongxian, Wu Ruqian
College of Physics and Electronic Engineering, Henan Normal University, Xinxiang, Henan 453007, People's Republic of China.
Phys Chem Chem Phys. 2014 May 14;16(18):8536-40. doi: 10.1039/c3cp55076a.
Using first principles simulations and the Monte Carlo method, the optimal structure of the triple-phase boundaries (TPB) of the Ni/Yttria-Stabilized Zirconia (YSZ) anode in solid oxide fuel cells (SOFCs) is determined. Based on the new TPB microstructures we reveal different reaction pathways for H2 and CO oxidation. In contrast to what was believed in previous theoretical studies, we find that the O spillover from YSZ to Ni plays a vital role in electrochemical reactions. The H2 oxidation reaction can proceed very rapidly, by means of both the H and O spillovers, whereas the CO oxidation can only proceed through the O spillover pathway. Further understanding of the roles of defects and dopants allows us to explain puzzling experimental observations and to predict ways to improve the catalytic performance of SOFCs.
利用第一性原理模拟和蒙特卡罗方法，确定了固体氧化物燃料电池（SOFC）中镍/钇稳定氧化锆（YSZ）阳极的三相边界（TPB）的最佳结构。基于新的TPB微观结构，我们揭示了H2和CO氧化的不同反应途径。与先前理论研究中所认为的不同，我们发现氧从YSZ溢出到Ni在电化学反应中起着至关重要的作用。H2氧化反应可以通过H和O的溢出非常迅速地进行，而CO氧化只能通过O溢出途径进行。对缺陷和掺杂剂作用的进一步理解使我们能够解释令人困惑的实验现象，并预测提高SOFC催化性能的方法。
