Iron fuel cell a basso costo
In un articolo pubblicato su Science (2009, 324, 71) leggiamo che un gruppo di ricercatori canadesi (National Institute for Scientific Research, in Quebec ) sono riusciti ad utilizzare il ferro quale catalizzatore a basso costo per le celle a combustibile (fuel cell ad idrogeno) che potrebbe benissimo sostituire il platino, molto più costoso, per generare elettricità ad uso automobilistico per i veicoli elettrici. Le (Polymer-electrolyte-membrane PEM) fuel cell più studiate proprio per le applicazioni automotive generalmente includono un catalizzatore a base di platino ( carbon-supported platinum -Pt/C), un metallo quindi relativamente raro e non certo a buon mercato, che permette le reazioni agli elettrodi generante corrente elettrica. Adesso sembra che sia stato trovato il modo per guidare la reazione di ossido-riduzione che converte l'ossigeno in acqua a livello del catodo.
Fonte Chemical & Engineering News
Iron-Based Catalysts with Improved Oxygen Reduction Activity in Polymer Electrolyte Fuel Cells
Michel Lefèvre, Eric Proietti, Frédéric Jaouen, and Jean-Pol Dodelet
Science 3 April 2009: 71-74.
Iron-based catalysts now rival traditional platinum fuel-cell catalysts.
Iron-based catalysts for the oxygen-reduction reaction in polymer electrolyte membrane fuel cells have been poorly competitive with platinum catalysts, in part because they have a comparatively low number of active sites per unit volume. We produced microporous carbon–supported iron-based catalysts with active sites believed to contain iron cations coordinated by pyridinic nitrogen functionalities in the interstices of graphitic sheets within the micropores. We found that the greatest increase in site density was obtained when a mixture of carbon support, phenanthroline, and ferrous acetate was ball-milled and then pyrolyzed twice, first in argon, then in ammonia. The current density of a cathode made with the best iron-based electrocatalyst reported here can equal that of a platinum-based cathode with a loading of 0.4 milligram of platinum per square centimeter at a cell voltage of 0.9 volt.
Institut National de la Recherche Scientifique, Énergie, Matériaux et Télécommunication, Varennes, Québec J3X 1S2, Canada.
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Fonte Chemical & Engineering News
Iron-Based Catalysts with Improved Oxygen Reduction Activity in Polymer Electrolyte Fuel CellsMichel Lefèvre, Eric Proietti, Frédéric Jaouen, and Jean-Pol Dodelet
Science 3 April 2009: 71-74.
Iron-based catalysts now rival traditional platinum fuel-cell catalysts.
Iron-based catalysts for the oxygen-reduction reaction in polymer electrolyte membrane fuel cells have been poorly competitive with platinum catalysts, in part because they have a comparatively low number of active sites per unit volume. We produced microporous carbon–supported iron-based catalysts with active sites believed to contain iron cations coordinated by pyridinic nitrogen functionalities in the interstices of graphitic sheets within the micropores. We found that the greatest increase in site density was obtained when a mixture of carbon support, phenanthroline, and ferrous acetate was ball-milled and then pyrolyzed twice, first in argon, then in ammonia. The current density of a cathode made with the best iron-based electrocatalyst reported here can equal that of a platinum-based cathode with a loading of 0.4 milligram of platinum per square centimeter at a cell voltage of 0.9 volt.
Institut National de la Recherche Scientifique, Énergie, Matériaux et Télécommunication, Varennes, Québec J3X 1S2, Canada.
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