During the project novel bi-metallic structures based on the archetypal MIL-127 (MIL = Material Institut Lavoisier), MIL-88’s and MIL-100 materials have been synthesized. To obtain the homometallic and bi-metallic materials, different routes were explored, mainly using low temperature synthesis and solvothermal reactions.
In parallel to the synthesis, complete structural and textural characterisation of the novel hetero-MOFs was developed. In situ infrared spectroscopy analysis was carried out on specific heterometallic MOFs to gain insights on the nature and the oxidation state of the accessible cations in the framework.
Finally, to validate the catalytic activity of the obtained heterometallic MOFs as compared to their parent homometallic material, we tested them in acid-catalyzed model reactions. It was found that for a certain metal substitution the catalytic activity improves more than one order of magnitude, with a complete selectivity. It is proposed that the insertion of new Lewis acid sites on the structure effectively promotes the formation of highly reactive defects, which could explain these catalytic performances. These heterometallic MOFs can be recycled in the absence of metal leaching, while maintaining the crystal structure in the reaction conditions.