Mechanism of H adatoms improving the O2 reduction reaction on the Zn-modified anatase TiO2 (101) surface studied by first principles calculation
Mechanism of H adatoms improving the O2 reduction reaction on the Zn-modified anatase TiO2 (101) surface studied by first principles calculation
复制标题
第一性原理计算研究H吸附原子促进Zn修饰锐钛矿型TiO2(101)表面O2还原反应的机理
DOI：
10.1039/c8dt00931g
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发表时间：
2018
影响因子：
4
通讯作者：
Yu Jia
中科院分区：
文献类型：
--
作者：
Liangliang Liu;Chongyang Li;Man Jiang;Xiaodong Li;Xiaowei Huang;Zhu Wang;Yu Jia
通过第一性原理计算，深入研究了Zn和H元素在TiO2（101）表面提高O2还原反应活性的机理.对于Zn改性的TiO2（101）表面，表面和亚表面的Zn介电层都能促进O2的吸附和解离，但O2分子的解离势垒仍然过高，限制了ORR活性。在Zn修饰的TiO2（101）表面上引入H原子后，其最高能垒比Zn修饰的TiO2（101）表面大大降低。同时，观察到解离势垒随初始态和过渡态构型之间吸附O2的电荷差的增大而几乎线性减小。具体地说，亚表面Zn和表面H介体促进O2解离和随后的氧化反应，进一步的频率分析表明，这些解离过程即使在300 K的室温下也是频繁的。总之，本工作为设计一种可与贵金属Pt催化剂相媲美的高氧还原活性的TiO2催化剂提供了理论支持。
First principles calculations were performed to cast insight into the mechanism of the improvement of O2 reduction reaction (ORR) activity by Zn and H interstitials on the anatase TiO2 (101) surface. For the Znmodified anatase TiO2 (101) surface, both surface and subsurface Zn interstitials could contribute to O2 adsorption and dissociation, but the dissociation barriers of O2 molecules are still too high, which limits the ORR activity. After a H adatom is introduced onto the Zn-modified anatase TiO2 (101) surface, the highest energy barriers are greatly reduced compared with those of the Zn-modified surface. Meanwhile,.it is observed that the dissociation barriers decrease almost linearly with the increase of the charge difference of adsorption O2 between initial and transition state configurations. Specifically, subsurface Zn and surface H interstitials facilitate O2 dissociation and subsequent oxidation reactions, and further frequency.analysis shows that these dissociation processes are frequent even at the room temperature of 300 K. In a word, this work provides a theoretical support to design a high ORR activity catalyst of the TiO2 nanocrystal comparable to precious Pt catalysts.