Département de chimie moléculaire

In the quest of new efficient and noble metal-free H2-evolution catalysts, hydrogenase enzymes are a source of inspiration. Here, we describe the development of a new hybrid material based on a structural and functional [NiFe]-hydrogenase model complex (NiFe) incorporated into the Zr-based MOF PCN-777. The bulk NiFe@PCN-777 material was synthesized by simple encapsulation. Characterization by solid state NMR and IR spectroscopies, SEM-EDX, ICP-OES and gas adsorption confirmed the inclusion of the guest. FTO-supported thin films of the NiFe@PCN-777 composite were obtained by electrophoretic deposition of the bulk material, and characterized by SEM-EDX, ICP-OES and cyclic voltammetry. The av. surface concn. of electroactive NiFe catalyst in the film was found to be of ∼9.6 × 10-10 mol.cm-2, implying that a surprisingly high fraction (37{%}) of NiFe units incorporated in the MOF are electroactive. By cyclic voltammetry, we showed that NiFe maintains its electrocatalytic capabilities for H+ redn. inside the MOF cavities, even if under controlled-potential electrolysis conditions the activity of NiFe cannot be discerned from that of free PCN-777 and FTO. [on SciFinder(R)]