Organometallic Complexes for Energy Production and Storage

Organometallic complexes have intrinsically excellent characteristics as a new class of electrocatalysts for clean energy production in fuel cells and electrolyzers. The state of the art materials for those devices are based on precious metal nanoparticles dispersed on a conductive carbon based supports. Despite the fact that such materials have reached very high performance levels in terms of activity and stability, they still suffer from some intrinsic limitations that contribute to hinder the commercial development of fuel cells and electrolyzers on a large scale. Organometallic-based electrocatalysts may help to overcome such limitations. For example, those devices exhibit remarkably high selectivity for alcohol electrooxidation towards carboxylic compunds of industrial relevance. Additionally, precious metal loadings can be reduced significantly by using single site organometallic catalysts where each metal atom is potentially active. Here we present a Rh organometallic catalyst, [Rh(OTf)(trop2NH){P(4-n-butyl-Ph)3}] (trop2NH=bis(5-H dibenzo[a,d]cyclohepten-5-yl)-amine; OTf- = CF3SO3- = triflate) that was successfully employed as anode both for Direct Alcohol Fuel Cells, named Organometallic Fuel Cells (OMFCs) and Alcohol Electroreformers, named Organometallic Electroreformers (OMERs). These devices exploit a biomass-derived alcohol (e.g. EtOH, 1,2-propanediol or glycerol) for respectively energy and hydrogen production and contemporaneously, the alcohol is converted in a high-added-value carboxylate, such as lactate. Therefore, we hypothesize the exploitation of OMFCs and OMERs as an essential component of the biorefinery platform. To the best of our knowledge, this [Rh(OTf)(trop2NH){P(4-n-butyl-Ph)3}] complex is the most active organometallic anode for OMFCs and OMERs ever reported.