Experimental and Theoretical Study of N2 Adsorption on Hydrogenated Y2C4H- and Dehydrogenated Y2C4- Cluster Anions at Room Temperature

The adsorption of atmospheric dinitrogen (N-2) on transition metal sites is an important topic in chemistry, which is regarded as the prerequisite for the activation of robust N equivalent to N bonds in biological and industrial fields. Metal hydride bonds play an important part in the adsorption of N-2, while the role of hydrogen has not been comprehensively studied. Herein, we report the N-2 adsorption on the well-defined Y2C4H0,1- cluster anions under mild conditions by using mass spectrometry and density functional theory calculations. The mass spectrometry results reveal that the reactivity of N-2 adsorption on Y2C4H- is 50 times higher than that on Y2C4- clusters. Further analysis reveals the important role of the H atom: (1) the presence of the H atom modifies the charge distribution of the Y2C4H- anion; (2) the approach of N-2 to Y2C4H- is more favorable kinetically compared to that to Y2C4-; and (3) a natural charge analysis shows that two Y atoms and one Y atom are the major electron donors in the Y2C4- and Y2C4H- anion clusters, respectively. This work provides new clues to the rational design of TM-based catalysts by efficiently doping hydrogen atoms to modulate the reactivity towards N-2.

Automated summary

This study reports on the N-2 adsorption on well-defined Y2C4H0,1- cluster anions under mild conditions. The results show that N-2 adsorption on Y2C4H- clusters is 50 times more reactive than on Y2C4- clusters. Further analysis reveals the important role of the H atom in modifying the charge distribution and facilitating the approach of N-2 to Y2C4H-.