Proton oxygen reduction

In this section, we summarize the kinetic behavior of the oxygen reduction reaction (ORR), mainly on platinum electrodes since this metal is the most active electrocatalyst for this reaction in an acidic medium. The discussion will, however, be restricted to the characteristics of this reaction in DMFCs because of the possible presence in the cathode compartment of methanol, which can cross over the proton exchange membrane. 

Muketjee S, Srinivasan S. 1993. Enhanced electrocatalysis of oxygen reduction on platinum alloys in proton exchange membrane fuel cells. J Electroanal Chem 357 201-224. 

As with the phase diagrams and Pourbaix diagrams, the theoretical standard hydrogen electrode also allows us to calculate the relative energies of intermediates in electrochemical reactions. As an example, we investigate the oxygen reduction reaction (ORR). We look at the four proton and electron transfer elementary steps ... 

Fernandez JL, Raghuveer V, Manthiram A, Bard AJ. 2005a. Pd-Ti and Pd-Co-Au electrocatalysts as a replacement for platinum for oxygen reduction in proton exchange membrane fuel cells. J Am Chem Soc 127 13100-13101. 

Mukeijee S, Srinivasan S. 1993. Enhanced electrocatalysis of oxygen reduction on platinum alloys in proton exchange membrane fuel cells. J Electroanal Chem 357 201-224. Mukeijee S, Srinivasan S, Soriaga M, McBreen J. 1995. Role of structural and electronic properties of Pt and Pt alloys on electrocatalysis of oxygen reduction. J Electrochem Soc 142 1409-1422. 

Kabbabi A, Gloaguen F, Andolfatto F, Durand R. 1994. Particle-size effect for oxygen reduction and methanol oxidation on Pt/C inside a proton-exchange membrane. J Electroanal Chem 373 251-254. 

Sometime probably two billion years before humans became interested in efficient catalysts for four-electron, four-proton reduction of O2 to H2O, the so-called oxygen reduction reaction (ORR),... 

Fuel cell applications Manganese dioxide as a new cathode catalyst in microbial fuel cells [118] OMS-2 catalysts in proton exchange membrane fuel cell applications [119] An improved cathode for alkaline fuel cells [120] Nanostructured manganese oxide as a cathodic catalyst for enhanced oxygen reduction in a microbial fuel cell [121] Carbon-supported tetragonal MnOOH catalysts for oxygen reduction reaction in alkaline media [122]... 

Fischer-Tropsch catalysis, 34 71, 38 331-335 C2 oxygenate formation, 38 338 oxide-supported osmium clusters, 38 335 product selectivites, 38 333-334 proton-induced reduction of CO, 38 332-333... 

Zhang, L., Ma, C. and Mukerjee, S. 2004. Oxygen reduction and transport characteristics at a platinum and alternative proton conducting membrane interface. Journal of Electroanalytical Chemistry 568 273-291. 

Concentrating on the operation of the so-called membrane electrode assembly (MEA), E includes irreversible voltage losses due to proton conduction in the PEM and voltage losses due to transport and activation of electrocatalytic processes involved in the oxygen reduction reaction (ORR) in the cathode catalyst layer (CCL) ... 

J.-M. Zen, C.-B. Wang, Oxygen Reduction on Ruthenium Oxide Pyrochlore Produced in a Proton Exchange Membrane, J. Electrochem. Soc. 141 (1994) 38-39. 

An additional problem arises from ethanol crossover through the proton exchange membrane. It results that the platinum cathode experiences a mixed potential, since both the oxygen reduction and ethanol oxidation take place at the same electrode. The cathode potential is therefore lower, leading to a decrease in the cell voltage and a further decrease in the voltage efficiency. 

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