Xie Wei, Koyama Michihisa
INAMORI Frontier Research Center , Kyushu University , 744 Motooka, Nishi-ku , Fukuoka , 819-0395 , Japan . Email:
Graduate School of Engineering , Hiroshima University , 1-4-1 Kagamiyama, Higashi-Hiroshima , Hiroshima 739-8527 , Japan.
Chem Sci. 2019 Apr 26;10(21):5461-5469. doi: 10.1039/c9sc00912d. eCollection 2019 Jun 7.
Based on the concept of density of states (DOS) engineering, we theoretically designed a pseudo-Tc material (Mo-Ru alloy) and investigated its electronic structure, phase stability and catalytic activity by using density functional theory. Through comparing the DOS shape, peak distribution, and DOS area differences between Tc and the Mo-Ru alloy, we noticed that bcc-MoRu and hcp-MoRu had the most similar electronic structures to Tc. The excess energies after entropy correction of hcp-MoRu and bcc-MoRu are stable when the temperature is up to 765 and 745 K, respectively. These results provided the possibility of pseudo-Tc alloy (hcp-MoRu and bcc-MoRu) synthesis. Finally, according to reaction coordinate analysis, the similar catalytic activity between hcp-MoRu and Tc have been demonstrated in CO oxidation and N dissociation. In N dissociation, Tc has a suitable ratio of transition state (TS) barrier to reaction energy which make Tc an efficient catalyst for NH synthesis, in addition to our designed pseudo-Tc (hcp-MoRu) because of the similar electronic structures. Our finding provides valuable insight into materials and catalyst design.
基于态密度（DOS）工程的概念，我们从理论上设计了一种赝Tc材料（Mo-Ru合金），并利用密度泛函理论研究了其电子结构、相稳定性和催化活性。通过比较Tc与Mo-Ru合金之间的DOS形状、峰分布和DOS面积差异，我们注意到体心立方结构的MoRu和六方密堆积结构的MoRu具有与Tc最相似的电子结构。当温度分别达到765K和745K时，六方密堆积结构的MoRu和体心立方结构的MoRu经熵校正后的过剩能量是稳定的。这些结果为赝Tc合金（六方密堆积结构的MoRu和体心立方结构的MoRu）的合成提供了可能性。最后，根据反应坐标分析，在CO氧化和N解离中，六方密堆积结构的MoRu与Tc表现出相似的催化活性。在N解离中，Tc具有合适的过渡态（TS）势垒与反应能量之比，这使得Tc成为合成NH的高效催化剂，此外，由于电子结构相似，我们设计的赝Tc（六方密堆积结构的MoRu）也是如此。我们的发现为材料和催化剂设计提供了有价值的见解。
