Das Shreeja, Nayak Saroj K, Sahu Kisor K
School of Minerals, Metallurgical and Materials Engineering, Indian Institute of Technology Bhubaneswar India
Centre of Excellence for Novel Energy Materials, Indian Institute of Technology Bhubaneswar India.
RSC Adv. 2020 Mar 31;10(22):12929-12940. doi: 10.1039/d0ra01835j. eCollection 2020 Mar 30.
Hydrogen interaction with metal atoms is of prime focus for many energy related applications like hydrogen storage, hydrogen evolution using catalysis, Although hydrogen binding with many main group alkaline and transition metals is quite well understood, its binding properties with lanthanides are not well reported. In this article, by density functional theory studies, we show how a rare earth metal, cerium, binds with hydrogen when decorated over a heteropolar 2D material, hexagonal boron nitride. Each cerium adatom is found to bind eight hydrogen molecules which is a much higher number than has been reported for transition metal atoms. However, the highest binding energy occurs at four hydrogen molecules. This anomaly, therefore, is investigated in the present article using first-principles calculations. The number density of hydrogen molecules adsorbed over the cerium adatom is explained by investigating the electronic charge volume interactions owing to a unique geometrical arrangement of the guest hydrogen molecules. The importance of geometrical encapsulation in enhancing electronic interactions is explained.
氢与金属原子的相互作用是许多与能源相关应用（如储氢、催化析氢）的主要研究重点。尽管氢与许多主族碱金属和过渡金属的结合已得到很好的理解，但其与镧系元素的结合特性却鲜有报道。在本文中，通过密度泛函理论研究，我们展示了稀土金属铈在异极二维材料六方氮化硼上修饰时与氢的结合方式。发现每个铈吸附原子可结合八个氢分子，这一数量比过渡金属原子所报道的要高得多。然而，最高结合能出现在四个氢分子处。因此，本文使用第一性原理计算对这一异常现象进行了研究。通过研究客体氢分子独特几何排列所导致的电子电荷体积相互作用，解释了吸附在铈吸附原子上的氢分子的数密度。解释了几何封装在增强电子相互作用中的重要性。
