The production of hydrogen by electrolysis of water is a well-established technology but it does not have a significant commercial impact due to its high energy cost. This is the main reason why it accounts for only a small proportion of the world's hydrogen production (circa 4%). A recent strategy for reducing the energy cost of electrolytic hydrogen production involves the replacement of water oxidation at the anode of the electrolytic cell with the oxidation of a soluble substrate, like a bioalcohol, whose oxidation potential is much lower than that of water. This leads to a significant reduction of the potential required to produce hydrogen. In the course of our studies of Direct Alcohol Fuel Cells, we have developed a new type of fuel cell called an Organo-Metallic Fuel Cell where the anode electrocatalyst is a molecular metal complex embedded in a conductive carbonaceous material. These electrocatalysts efficiently catalyze the conversion of primary alcohols and polyols into the corresponding carboxylic acid derivatives producing at the same time electrical power. The original idea presented here, consists in coupling the partial oxidation of renewable alcohols promoted by an organometallic complex [Rh(OTf)(trop2NH){P(4-n-butyl-Ph)3}] (trop2NH=bis(5-H dibenzo[a,d]cyclohepten-5-yl)-amine; OTf- = CF3SO3- = triflate; (see 1@C in figure 1 for a structure plot) with the cathodic hydrogen evolution reaction. We report an electrolytic device that achieves the simultaneous selective production of carboxylate compounds and high-purity hydrogen gas. This electrolyzer, that we call OrganoMetallic ElectroReformer (OMER), in contrast to electrolysis technologies based on nanoparticles, offers potentially enormous advantages as in principle every single metal atom is catalytically active, thus allowing a vastly reduced metal loading. At the same time, this technology represents a novel chemical process for the generation of bio-sourced chemicals from a large variety of alcohols
Hydrogen and Chemicals from renewable alcohols by Organometallic Electro-Reforming (OMER)
2016
Abstract
The production of hydrogen by electrolysis of water is a well-established technology but it does not have a significant commercial impact due to its high energy cost. This is the main reason why it accounts for only a small proportion of the world's hydrogen production (circa 4%). A recent strategy for reducing the energy cost of electrolytic hydrogen production involves the replacement of water oxidation at the anode of the electrolytic cell with the oxidation of a soluble substrate, like a bioalcohol, whose oxidation potential is much lower than that of water. This leads to a significant reduction of the potential required to produce hydrogen. In the course of our studies of Direct Alcohol Fuel Cells, we have developed a new type of fuel cell called an Organo-Metallic Fuel Cell where the anode electrocatalyst is a molecular metal complex embedded in a conductive carbonaceous material. These electrocatalysts efficiently catalyze the conversion of primary alcohols and polyols into the corresponding carboxylic acid derivatives producing at the same time electrical power. The original idea presented here, consists in coupling the partial oxidation of renewable alcohols promoted by an organometallic complex [Rh(OTf)(trop2NH){P(4-n-butyl-Ph)3}] (trop2NH=bis(5-H dibenzo[a,d]cyclohepten-5-yl)-amine; OTf- = CF3SO3- = triflate; (see 1@C in figure 1 for a structure plot) with the cathodic hydrogen evolution reaction. We report an electrolytic device that achieves the simultaneous selective production of carboxylate compounds and high-purity hydrogen gas. This electrolyzer, that we call OrganoMetallic ElectroReformer (OMER), in contrast to electrolysis technologies based on nanoparticles, offers potentially enormous advantages as in principle every single metal atom is catalytically active, thus allowing a vastly reduced metal loading. At the same time, this technology represents a novel chemical process for the generation of bio-sourced chemicals from a large variety of alcoholsI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.