Role of Hydrogen Bonding on Transport of Coadsorbed Gases in Metal-Organic Frameworks Materials.

Coadsorption of multicomponents in metal-organic framework (MOF) materials can lead to a number of cooperative effects, such as modification of adsorption sites or during transport. In this work, we explore the incorporation of NH and HO into MOFs preloaded with small molecules such as CO, CO, and SO. We find that NH (or HO) first displaces a certain amount of preadsorbed molecules in the outer portion of MOF crystallites, and then substantially hinders diffusion. Combining in situ spectroscopy with first-principles calculations, we show that hydrogen bonding between NH (or HO) is responsible for an increase of a factor of 7 and 8 in diffusion barrier of CO and CO through the MOF channels. Understanding such cooperative effects is important for designing new strategies to enhance adsorption in nanoporous materials.