Mechanical, electronic, and adsorption properties of porous aromatic frameworks

Diamond-like porous aromatic frameworks (PAFs) form a new set of materials that contain only carbon and hydrogen atoms within their frameworks. These structures have very low mass densities, large surface area, and high porosity. Density-functional-based calculations indicate that crystalline PAFs have mechanical stability and properties similar to those of covalent organic frameworks. Their exceptional structural properties and stability make PAFs interesting materials for hydrogen storage. Our theoretical investigations show exceptionally high hydrogen uptake at room temperature, which can reach 7 wt %, a value exceeding those of well-known metal- and covalent-organic frameworks (MOFs and COFs). For an exemplary PAF with long linkers (PAF-304), we have studied the effect of interpenetration on properties as mechanical stability and hydrogen storage.