Introduction:

The success of future hydrogen and fuel-cell technologies is critically dependent upon the discovery of new materials that can store large amounts of hydrogen at ambient conditions. Metal-organic framework (MOF) compounds, which consist of metal-oxide clusters connected by organic linkers, are a relatively new class of nano-porous material that show promise for hydrogen storage applications because of their tunable pore size and functionality. Yet despite numerous experimental studies of hydrogen adsorption in MOF materials, the nature of the MOF-hydrogen interaction and the manner in which hydrogen molecules are adsorbed onto the structure are still unknown. Answers to these questions hold the key to optimizing these materials for practical hydrogen storage applications.