Hydrogen Storage Efficiency of the Ag (I)/Au (I) Decorated Five-Member Aromatic Heterocyclic (AH) Compounds: A Theoretical Investigation

Abhishek Bag1,2

Swapan Sinha1

Himadri Sekhar Das1,3

Santanab Giri1

Gobinda Chandra De2

Sibaprasad Maity4

Ben Bin Xu5

Zhanhu Guo5

Jhuma Ganguly6

Gourisankar Roymahapatra1,Email

1School of Applied Sciences and Humanities, Haldia Institute of Technology, ICARE Complex, Haldia 721657, WB, India.

2Department of Chemistry, Cooch Behar Panchanan Barma University, Cooch Behar 736101, WB, India.

3Department of ECE, Haldia Institute of Technology, ICARE Complex, Haldia 721657, WB, India.

4Department of Chemistry, Sagardighi Kamada Kinkar Smriti Mahavidyalaya, Sagardighi 742226, WB, India.

5Mechanical and Construction Engineering, Faculty of Engineering and Environment, Northumbria University, Newcastle Upon Tyne NE1 8ST, UK.

6Department of Chemistry, Indian Institute of Engineering Science and Technology, Howrah 711103, WB, India.

Abstract

The hydrogen (H2) economy has long faced significant challenges in the areas of production, storage, and application. Extensive research efforts have been directed towards finding effective solutions. Among the various storage options, solid-state hydrogen storage has emerged as a promising alternative. In this study, we conduct a theoretical investigation on the efficiency of H2 trapping in Ag(I)/Au(I)-decorated five-member aromatic heterocyclic (AH) rings. We analyze the aromaticity of the metal-decorated ring and the H2-trapped metal-decorated ring using the nuclear independent chemical shift (NICS) value, to study the stability of the aromatic system. Our findings also demonstrate that these systems are capable of trapping up to five molecules of H2 in a quasi-sorption manner. Furthermore, we investigate the spontaneity of H2 adsorption in Ag(I)/Au(I)-decorated systems by examining the Gibbs free energy change. To understand the bonding nature, we perform an analysis using the electron localization function (ELF) and non-covalent interaction (NCI) analysis, which reveal the bonding nature of our modeled systems. It has shown the gravimetric wt% values ranging from 3.66 to 5.45. Additionally, the partial density of states (PDOS) technique is employed to identify the contributions of H2, decorated metal, and the five-member AH system towards the frontier molecular orbitals of the complexes.

Hydrogen Storage Efficiency of the Ag (I)/Au (I) Decorated Five-Member Aromatic Heterocyclic (AH) Compounds: A Theoretical Investigation