Aluminum metal–organic frameworks for sorption in solution: A review

This Review covers the progress of research on sorption on aluminum metal–organic frameworks, Al-MOFs in the liquid phase within the recent 5 years and the relevant earlier reports. Al-MOFs show the versatility in the structure, an exceptional chemical and structural stability at the elevated temperatures, in air, water and organic solvents, high capacity and selectivity in the sorption, separations, purification, heterogeneous catalysis, sensing. This focused critical Review includes the research on the following aspects of Al-MOFs: 1) their activation and thermal stability; 2) stability in water and aqueous solutions; 3) sorption of organic dyes, miscellaneous organic and inorganic compounds in water; 4) stability in organic solvents, and sorption of organic compounds of various classes e.g. N-heterocyclic and S-heterocyclic compounds from liquid fuels, and 5) the industrial-scale synthesis and emerging large-scale applications. The perspectives and limitations of a wide industrial use of Al-MOFs are outlined. The particular focus is on the mechanisms of activation and molecular interactions with the adsorbate during the sorption/desorption: the π-π, Lewis and Brønsted acid-base interactions, ionic, coordination and hydrogen bonding, “breathing”, sterical match between the “guest” molecule and nanopores in Al-MOFs, and non-specific interactions. The current knowledge gaps are highlighted and the unexplored application niches are revealed.