Catalytic properties toward the Oxygen Reduction Reaction of 2D metal-organic frameworks: metal porphyrins on Au(111)

J.M. LOMBARDI; D. GRUMELLI; R. GUTZER; K. KERN; H. F. BUSNENGO; P. ABUFAGER

San Sebastian

Workshop; Photo and ElectroCatalysis at the Atomic Scale (PECAS 2022); 2022

In general, metal porphyrins adsorb flat on metal surfaces being theSAM structure ruled by the subtle interplay between molecule-moleculeand molecule-surface interactions. In the case of metal tetrapyridyl-porphyrins (M-TPyP) the lattice parameter of the SAM not only fixes thenumber of (metal) active sites per unit area but is also crucial to allow(or not) the pyridyl nitrogens to offer an additional coordination site forextra metal atoms which might proceed from surface environment orfrom the surface itself. In addition, it has been experimentally shownthat metal atoms M’ sublimated over the M-TPyP/Au(111) SAM can alsosubstitute the M center , so being able to modify its electrocatalyticactivity in quite many ways. In this work we present a DensityFunctional Theory (DFT) study of the structure and electrocatalyticactivity for the oxygen reduction reaction (ORR) of both theFeTPyP/Au(111) SAM, and the resulting bimetal-organic frameworkFeTPyP+M’/Au(111) obtained by sublimation of M’ (=Fe, Co) atoms. Weanalyze the role of intermolecular, and molecule-Au(111) interactions onthe structure of the mono- and bi- metal organic SAMs, and theirelectrocatalytic activities considering all the many possible resultingmetal active sites.