title: Metal organic framework synthesis in the presence of surfactants: towards hierarchical MOFs?
abstract: The effect of synthesis pH and H2O/EtOH molar ratio on the textural properties of different aluminium trimesate metal organic frameworks (MOFs) prepared in the presence of the well-known cationic surfactant cetyltrimethylammonium bromide (CTAB) at 120 °C was studied with the purpose of obtaining a MOF with hierarchical pore structure. Depending on the pH and the solvent used, different topologies were obtained (namely, MIL-96, MIL-100 and MIL-110). On the one hand, MIL-110 was obtained at lower temperatures than those commonly reported in the literature and without additives to control the pH; on the other hand, MIL-100 with crystallite sizes as small as 30 ± 10 nm could be easily synthesized in a mixture of H2O and EtOH with a H2O/EtOH molar ratio of 3.4 at pH 2.6 in the presence of CTAB. The resulting material displays a hierarchical porosity that combines the microporosity from the MOF and the non-ordered mesopores defined in between the MOF nanoparticles. Interestingly, the maximum of the pore size distribution could be varied between 3 and 33 nm. Finally, at pH 2.5 and using water as a solvent, platelets of MIL-96, a morphology never observed before for this MOF, were synthesized with a (001) preferential crystal orientation, the (001) plane running parallel to the bipyramidal cages of the MIL-96 topology.
authors.affiliation: Catalysis Engineering , ChemE , Delft University of Technology , Julianalaan 136 , 2628 BL Delft , The Netherlands . Email: B.SeoanedelaCuesta@tudelft.nl ; Email: j.gascon@tudelft.nl ; ; Tel: +31 1527 84851.
authors.forename: B
authors.initials: B
authors.lastname: Seoane
authors.affiliation: Catalysis Engineering , ChemE , Delft University of Technology , Julianalaan 136 , 2628 BL Delft , The Netherlands . Email: B.SeoanedelaCuesta@tudelft.nl ; Email: j.gascon@tudelft.nl ; ; Tel: +31 1527 84851.
authors.forename: A
authors.initials: A
authors.lastname: Dikhtiarenko
authors.affiliation: Chemical and Environmental Engineering Department and Nanoscience Institute of Aragon (INA) , Universidad de Zaragoza , Mariano Esquillor , Edificio I+D , 50018 , Zaragoza , Spain ; Advanced Microscopy Laboratory (LMA) , Nanoscience Institute of Aragon (INA) , Universidad de Zaragoza , Mariano Esquillor , Edificio I+D , 50018 , Zaragoza , Spain.
authors.forename: A
authors.initials: A
authors.lastname: Mayoral
authors.affiliation: Chemical and Environmental Engineering Department and Nanoscience Institute of Aragon (INA) , Universidad de Zaragoza , Mariano Esquillor , Edificio I+D , 50018 , Zaragoza , Spain.
authors.forename: C
authors.initials: C
authors.lastname: Tellez
authors.affiliation: Chemical and Environmental Engineering Department and Nanoscience Institute of Aragon (INA) , Universidad de Zaragoza , Mariano Esquillor , Edificio I+D , 50018 , Zaragoza , Spain.
authors.forename: J
authors.initials: J
authors.lastname: Coronas
authors.affiliation: Catalysis Engineering , ChemE , Delft University of Technology , Julianalaan 136 , 2628 BL Delft , The Netherlands . Email: B.SeoanedelaCuesta@tudelft.nl ; Email: j.gascon@tudelft.nl ; ; Tel: +31 1527 84851.
authors.forename: F
authors.initials: F
authors.lastname: Kapteijn
authors.affiliation: Catalysis Engineering , ChemE , Delft University of Technology , Julianalaan 136 , 2628 BL Delft , The Netherlands . Email: B.SeoanedelaCuesta@tudelft.nl ; Email: j.gascon@tudelft.nl ; ; Tel: +31 1527 84851.
authors.forename: J
authors.initials: J
authors.lastname: Gascon