Materilas Genome Institute, Shanghai University , 99 Shangda Road, Shanghai 200444, China.
J Am Chem Soc. 2015 Oct 28;137(42):13572-9. doi: 10.1021/jacs.5b07792. Epub 2015 Oct 15.
Unraveling the descriptor of catalytic activity, which is related to physical properties of catalysts, is a major objective of catalysis research. In the present study, the first-principles calculations based on interfacial model were performed to study the oxygen evolution reaction mechanism of Li2O2 supported on active surfaces of transition-metal compounds (TMC: oxides, carbides, and nitrides). Our studies indicate that the O2 evolution and Li(+) desorption energies show linear and volcano relationships with surface acidity of catalysts, respectively. Therefore, the charging voltage and desorption energies of Li(+) and O2 over TMC could correlate with their corresponding surface acidity. It is found that certain materials with an appropriate surface acidity can achieve the high catalytic activity in reducing charging voltage and activation barrier of rate-determinant step. According to this correlation, CoO should have as active catalysis as Co3O4 in reducing charging overpotential, which is further confirmed by our comparative experimental studies. Co3O4, Mo2C, TiC, and TiN are predicted to have a relatively high catalytic activity, which is consistent with the previous experiments. The present study enables the rational design of catalysts with greater activity for charging reactions of Li-O2 battery.
揭示与催化剂物理性质相关的催化活性描述符是催化研究的主要目标。在本研究中，我们基于界面模型进行了第一性原理计算，以研究负载在过渡金属化合物（TMC：氧化物、碳化物和氮化物）活性表面上的 Li2O2 的氧气析出反应机制。我们的研究表明，O2 析出和 Li(+)脱附能分别与催化剂表面酸度呈线性和火山关系。因此，TMC 上的 O2 析出和 Li(+)的充电电压和脱附能与其相应的表面酸度相关。研究发现，具有适当表面酸度的某些材料可以在降低充电电压和降低速率决定步骤的活化能垒方面实现高催化活性。根据这种相关性，CoO 在降低充电过电势方面应该具有与 Co3O4 相当的活性，这进一步通过我们的对比实验研究得到了证实。预测 Co3O4、Mo2C、TiC 和 TiN 具有较高的催化活性，这与先前的实验结果一致。本研究为设计具有更高 Li-O2 电池充电反应活性的催化剂提供了理论依据。
