Electrocatalyst for oxygen reduction

Several activities, if successful, would strongly boost the prospects for fuel ceU technology. These include the development of (/) an active electrocatalyst for the direct electrochemical oxidation of methanol (2) improved electrocatalysts for oxygen reduction and (2) a more CO-tolerant electrocatalyst for hydrogen. A comprehensive assessment of the research needs for advancing fuel ceU technologies, conducted in the 1980s, is available (22). 

Lee JW, Popov BN (2007) Ruthenium-based electrocatalysts for oxygen reduction reaction—a review. J Solid State Electrochem 11 1355-1364... 

Lee K, Zhang L, Zhang J (2007) Ternary non-noble mefal chalcogenide (W-Co-Se) as electrocatalyst for oxygen reduction reaction. Electrochem Commun 9 1704-1708... 

Stamenkovic V, Mun BS, Mayrhofer KJJ, Ross PN, Markovic NM, Rossmeisl J, Greeley J, Nprskov JK. 2006. Changing the activity of electrocatalysts for oxygen reduction by tuning the surface electronic structure. Angew Chem Int Ed 45 2897. 

Sasaki K, Zhang L, Adzic RR. 2008. Niobium oxide-supported platinum ultra-low amount electrocatalysts for oxygen reduction. Phys Chem Chem Phys 10 159-167. 

Shao MH, Huang T, Liu P, Zhang J, Sasaki K, Vukmirovic MB, Adzic RR. 2006a. Palladium monolayer and palladium alloy electrocatalysts for oxygen reduction. Langmuir 22 10409-10415. 

Shao MH, Sasaki K, Adzic RR. 2006c. Pd-Fe nanoparticles as electrocatalysts for oxygen reduction. J Am Chem Soc 128 3526-3527. 

Zhang J, Vukmirovic MB, Xu Y, Mavrikakis M, Adzic RR. 2005a. Controlling the catalytic activity of platinum-monolayer electrocatalysts for oxygen reduction with different substrates. Angew Chem Int Ed 44 2132-2135. 

Lalande G, Cote R, Tamizhmani G, Guay D, Dodelet JP. 1995. Physical, chemical and electrochemical characterization of heat-treated tetracarboxylic cobalt phthalocyanine adsorbed on carbon black as electrocatalyst for oxygen reduction in polymer electrolyte fuel cells. Electrochim Acta 40 2635-2646. 

Yang H, Alonso-Vante N, Leger JM, Lamy C. 2004. Tailoring, structure, and activity of carbon-supported nanosized Pt-Cr alloy electrocatalysts for oxygen reduction in pure and methanol-containing electrolytes. J Phys Chem 108 1938-1947. 

Khorasani-Motlagh M, Noroozifar M, Ghaemi A, Safari N. 2004. Iron(III) octaethylporphyrin chloride supported on glassy carbon as an electrocatalyst for oxygen reduction. J Electroanal Chem 565 115. 

The electrocatalysts for oxygen reduction were prepared as follows. These complex compounds were inoculated onto the carbon (AG-3, BET area near 800 m2/g) by means of adsorption from dimethylformamide solutions. The portion of complex compound weighed so as to achieve 3% of Co content was mixed with the carbon, then 5 ml of dimethylformamide per 1 g of the carbon were added and the mixture was cured at room temperature for 24 hours. Series of samples obtained were thermally treated (pyrolyzed), and the resulting grafted carbons were tested as electrode materials in the reaction of molecular oxygen reduction. 

J. Liang, Y. Jiao, M. Jaroniec, S. Z. Qiao, Sulfur and nitrogen dual-doped mesoporous graphene electrocatalyst for oxygen reduction with synergistically enhanced performance, Angew. Chem. Int. Ed., vol. 51, pp. 1-6, 2012. 

Y. D. Jin, Y. Shen, and S. J. Dong, Electrochemical design of ultrathin platinum-coated gold nanoparticle monolayer films as a novel nanostructured electrocatalyst for oxygen reduction, J. Phys. Chem. B 108, 8142-8147 (2004). 

Another prospect for eflBcient energy conversion is the fuel cell. The diflFerent types of fuel cells presently under study or development were reviewed by G. Belanger of Hydro-Quebec, who concluded that commercial availability of such units is now in sight. However, the need to develop cheap, efficient electrocatalysts for oxygen reduction remains. 

Transition metal compounds, such as organic macrocycles, are known to be good electrocatalysts for oxygen reduction. Furthermore, they are inactive for alcohol oxidation. Different phthalocyanines and porphyrins of iron and cobalt were thus dispersed in an electron-conducting polymer (polyaniline, polypyrrole) acting as a conducting matrix, either in the form of a tetrasulfonated counter anion or linked to... 

The application of gold as an electrocatalytic component within the fuel cell itself has to date been limited primarily to the historical use of a gold-platinum electrocatalyst for oxygen reduction in the Space Shuttle/Orbiter alkaline fuel cells (AFC)88 and the recent use of gold for borohydride oxidation in the direct borohydride alkaline fuel cell (DBAFC).89,90 Electrocatalysts with lower cost, improved carbon monoxide tolerance and higher... 

Previously, the first reviews on alloy electrocatalysts for oxygen reduction in phosphoric acid fuel-cells44"46 concentrated on those patents that had been issued in the United States, since that was where most of the early work had been done. Subsequendy, similar alloy work has been done in Japan, and that work is reflected in the Japanese patent literature shown in Table 3, whence corresponding alloy-combination atom ratios and the air/oxygen performance values are given in Table 3a. 

Bouwman, P.J. et al., Platinum-iron phosphate electrocatalysts for oxygen reduction in PEMFCs, J. Electrochem. Soc., 151, A1989, 2004. 

Gojkovic, S.L., Gupta, S., and Savinell, R.F., Heat-treated iron(lll) tetramethoxyphe-nyl porphyrin chloride supported on high-area carbon as an electrocatalyst for oxygen reduction, Electrochim. Acta, 45, 889, 1999. 

III. CASE STUDY Pt-Co ALLOY ELECTROCATALYSTS FOR OXYGEN REDUCTION... 

Fernandez et al. used a combined high throughput electrocatalyst study and DFT study to examine Pd-Co electrocatalysts for oxygen reduction. They screened an array of electrocatalysts using a scanning electrochemical microscope to assess the activity of each element. The DFT study was performed to help identify the role of Co in the system. They examined oxygen molecule adsorption, dissociation and... 

N. Alonso-Vante, M. Giersig, H. Tributsch, Thin layer semiconducting cluster electrocatalysts for oxygen reduction. J. Electrochem. Soc. 1991, 138, 639-640. 

Systematic studies of the role of such factors as the nature of the metal center and the detailed structure of the chelating ring, particularly its peripheral functionalization, can afford valuable information toward unveiling structure-activity relationships for macrocycles as electrocatalysts for oxygen reduction. The following sub-sections describe some of the most salient aspects of a selected number of transition metal phthalocyanines and porphyrins, including the effects of redox and non-redox active substituents on the properties of Co porphyrins. 

To circumvent the problem of methanol crossover in direct oxidation fuel cells, there has been continued effort to identify potential electrocatalysts for oxygen reduction which are insensitive to methanol oxidation, such as metal... 

R.H. Castellanos, A. Campero, O. Solorza-Feria, Synthesis of W-Se-Os carbonyl electrocatalyst for oxygen reduction in 0.5 M H2SO4, Int J. Hyd. Energy 23 (1998) 1037-1040. 

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