Theoretical design of a technetium-like alloy and its catalytic properties†
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-Mo8Ru8 and hcp-Mo8Ru8 had the most similar electronic structures to Tc. The excess energies after entropy correction of hcp-Mo8Ru8 and bcc-Mo8Ru8 are stable when the temperature is up to 765 and 745 K, respectively. These results provided the possibility of pseudo-Tc alloy (hcp-Mo8Ru8 and bcc-Mo8Ru8) synthesis. Finally, according to reaction coordinate analysis, the similar catalytic activity between hcp-Mo8Ru8 and Tc have been demonstrated in CO oxidation and N2 dissociation. In N2 dissociation, Tc has a suitable ratio of transition state (TS) barrier to reaction energy which make Tc an efficient catalyst for NH3 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.
- This article is part of the themed collection: 2019 Chemical Science HOT Article Collection