The synthesis, activation, and adsorption capacity of metal-organic frameworks for hydrogen storage

Abstract

Metal-organic frameworks (MOFs) comprise both organic and inorganic parts, allowing for immense diversity and tunability for specific purposes. Hydrogen has a hopeful prospect of being a clean energy carrier because of its lightness and therefore energy density, and it has been reported that MOFs already effectively adsorb hydrogen at cryogenic temperatures. In this article, the main synthesis methods for MOFs for hydrogen storage will be outlined, including the solvothermal, sonochemical, electrochemical and microwave methods. Methods of activation and stability concerns (thermal, mechanical and moisture) will also be addressed. The main focus of the article will be on increasing hydrogen capacity in MOFs at room temperature as opposed to cryogenic. The main ways to achieve this are adjusting pore size and strengthening hydrogen-MOF interaction. Recent research has shown that the most important effects in this regard are generating active metal sites, the spillover mechanism, and adjusting organic linkers.