Electrocatalysis in Fuel Cells

Electrocatalysis in fuel cells requires as well substances capable of catalyzing the anodic oxidation of fuels as catalysts for the cathodic reduction of oxygen. Several dyestuffs that catalyze oxygen reduction are known, but up to now only one has been described as active in anodic reactions. All these dyestuffs are N4-chelates. 

In chemical heterogeneous catalysis, it is common to use highly porous catalysts that come in particles of millimeter to centimeter size to increase the effective catalyst surface. In practical electrocatalysis, in particular applying electrocatalysis in fuel cells, it is also usual to use highly porous— although accounting for the low diffusion coefficients in liquid electrolytes compared to gases, 10 5 cm2/sec vs 1 cm2/sec, much smaller—catalyst particles. 

Also for cathodic oxygen reduction in low-temperature fuel cells, platinum is indispensible as a catalyst whereas the cathodic electrocatalysts in MCFCs and SOFCs are lithiated nickel oxide and lanthanum-manganese per-ovskite, respectively. Appleby and Foulkes in the Fuel Cell Handbook (101) reviewed the fundamental work as well as the technologically important publications covering electrocatalysis in fuel cells till 1989. 

M. Shao (ed.), Electrocatalysis in Fuel Cells, Lecture Notes in Energy 9, DOI 10.1007/978-1-4471-4911-8 1, Springer-Verlag London 2013... 

Hayden, B. E. and J. Suchsland. 2009. Support and Particle Size Effects in Electrocatalysis, in Fuel Cell Catalysis—A Surface Science Approach, editor, M. T. M. Koper, 567-592. Hoboken, New Jersey John Wiley Sons. 

Higgins D, Chen Z (2013) Electrocatalysis in fuel cells. In Shao M (ed) Lecture Notes in Energy Ch. 9, vol 9. Springer, London, pp 247-269... 

Dodelet JP (2013) The controversial role of the metal in Fe- or Co-based electrocatalysts for the oxygen reduction reaction in acid medium. In Shao M (ed) Electrocatalysis in fuel cells a non- and low-platinum approach. Springer London, United Kingdom, pp. 271-338, ISBN 978-1 71 910-1... 

The application of first principles methods to the study of electrocatalysis in fuel cells has gained significant momentum in recent years. Browse any issue of a journal with theoretical electrochemistry content and you will notice a few theoretical study articles. Theoretical modeling in electrochemistry has certainly reached the stage at which it can begin to complement experimental methods, and provide insight into the atomic scale features that control the chemistry at the aqueous/metal interface [101]. 

---