DFT-based evaluation of porous metal formates for the storage and separation of small molecules

摘要: Abstract Microporous metal formates with the α-Mg(fa) 2 structure (fa = formate, − OOCH) have attracted considerable interest as materials for storage and separation of small guest molecules. In this study, dispersion-corrected density-functional theory (DFT-D) calculations are employed to calculate interaction energies five molecules (acetylene, carbon dioxide, methane, nitrogen, hydrogen) adsorbed in pores different centres (Mg, Mn, Fe, Co, Zn). For each guest-adsorbent combination, average strength is calculated Boltzmann-weighted DFT-D obtained individual adsorption sites. systems which experimentally measured heats been reported, averaged agree very well experimental values. Therefore, results can be used predict potential adsorbents applications. While may limited use many gas applications due their free volume, high affinity Co(fa) Zn(fa) towards methane acetylene could render them interesting more important than uptake capacity. With regard purification, emerges most attractive system selective dioxide over other species, while Mg(fa) promising from nitrogen or hydrogen. Correlations between simple descriptors pore size volume analysed.