Author(s)

Gaili Sun^1,2, Yuanyuan Li¹, Xinxin Zhao², Yiming Mi^1,2*, Lili Wang^2*

¹College of Chemistry and Chemical Engineering, Shanghai University of Engineering Science, Shanghai, China.
²College of Fundamental Studies, Shanghai University of Engineering Science, Shanghai, China.

First-principles calculations were used to study the energetics and electronic structures of Ni and Sc co-doped MgH₂ system. The preferential positions for dopants were determined by the minimal total electronic energy. The results of formation enthalpy indicate that Ni and Sc co-doped MgH₂ system is more stable than Ni single-doped system. The hydrogen desorption enthalpies of these two hydrides are investigated. Ni and Sc co-doping can improve the dehydrogenation properties of MgH₂. The lowest hydrogen desorption enthalpy of 0.30 eV appears in co-doped system, which is significantly lower than that of Ni doping. The electronic structure analysis illustrates that the hybridization of dopants with Mg and H atom together weakens the Mg-H interaction. And the Mg-H bonds are more susceptible to dissociate by Ni and Sc co-doping because of the reduced magnitude of Mg-H hybridization peaks. These behaviors effectively improve the dehydrogenation properties of Ni and Sc co-doped cases.

First-Principles Calculation, MgH₂, Stability, Enthalpy, Dehydrogenation Property, Electronic Structure

Sun, G. , Li, Y. , Zhao, X. , Mi, Y. and Wang, L. (2016) First-Principles Investigation of Energetics and Electronic Structures of Ni and Sc Co-Doped MgH₂. American Journal of Analytical Chemistry, 7, 34-42. doi: 10.4236/ajac.2016.71004.