Model electrocatalyst

GustavssonM, Fredriksson H, Kasemo B, Jusys Z, Jun C, Behm RJ. 2004. Nanostructured platinum-on-carbon model electrocatalysts prepared by colloidal lithography. J Electroanal Chem 568 371-377. 

Sufficiently far from equilibrium, which is the only interesting regime for current generation, the Tafel law (129), (130) with effective parameters is used in the simulations. Measurements performed on model electrocatalysts suggest different values for these parameters depending on the particular catalysts used or just their different structure. The mesoscopic effects in electrocatalysis are the hot topic nowadays [127, 187-189] and they are probable candidates for one of the reasons of this variance. The main cause of this variance may be associated with the complicated interplay between adsorption and reaction stages, and a modeler interested in fuel... 

By varying the particle size, shapes, separation, and support on planar model electrocatalysts, the influence of these properties on the electrocatal3dic reactions, e.g., on fuel cell electrodes, can be evaluated systematically. Some new challenges arise, such as the adhesion of the catalyst particles on new types of support materials (e.g., glassy carbon). However, most of the procedures and concepts of preparation and characterization are the same as in heterogeneous catalysis and photocatalysis. 

Lucas, C.A., Cromack, M., Gallagher, M.E. et al. (2008) From ultra-high vacuum to the electrochemical interface X-ray scattering studies of model electrocatalysts. Earaday Discussions, 140, 41-58. 

Once we have developed our basic model and shown how it may be used to estab-hsh trends in electrochemical reactivity, we will take the further step of applying it to the identification of new bimetallic electrocatalysts. We will introduce simple procedures to rapidly screen bimetallic alloys for promising electrocatalytic properties, and we will demonstrate the importance of including estimates of the alloys stabihty in the screening procedure. Finally, we will give examples of successful apphcation of this method to specific problems in the area of electrocatalyst development. 

Markovic NM, Ross PN. 2002. Surface science studies of model fuel cell electrocatalysts. Surf Sci Rep 45 121-229. 

MaiUard F, Lu GQ, Wieckowski A, Stimnting U. 2005. Ru-decorated Pt surfaces as model fuel cell electrocatalysts for CO electrooxidation. J Phys Chem B 109 16230-16243. 

Cost targets exist for all parts of the fuel cell for bipolar plates, from 10/kW (2004) to 3/kW in 2015 for electrocatalysts, from 40/kW (2005) to 3/kW in 2015 and for membrane electrode assemblies (MEA), from 50/kW (2005) to 5/kW in 2015 (Freedom Car, 2005 these cost targets are somewhat different from those mentioned by the IEA (2005)). Since 2004, the number of fuel-cell cars has been growing and at the time of writing they numbered approximately 1000 worldwide there are also around 100 fuel-cell buses in use worldwide in several demonstration projects. But these cars are produced as individual (hand-built) models and are extremely expensive, with production costs per vehicle currently estimated at around one million large-scale production is not expected before 2015, see Section 13.1. 

Vitamin B12 derivatives and their model compounds have recently been used as recyclable electrocatalysts for the reduction of alkyl halides since low-valent Co species are good nucleophiles toward organic substrates [367-369]. Examples of such elec-trocatalysts are the vitamin B12 derivatives aquocobalamin (230), dibromo[l-hydr-oxy-2,2,3,3,7,7,8,8,12,12,13,13,17,17,18,18-hexadecamethyl-10,20-diazaoctahydropor-phinato]cobalt(III) (231), and cobaloxim (232). The above Co(I) complexes can be... 

Advanced discovery of new electrocatalyst formulations is increasingly dominated by two techniques high-throughput screening of both model and practical catalyst materials and computational approaches to identify new active surfaces through theory. 

Direct metal deposition from metallic sources has been extensively used for model catalyst deposition for high-throughput and combinatorial studies. However, these methods are also increasingly used to deposit practical electrocatalyst materials. The best known approach is the one developed by 3M researchers have used physical vapor deposition to deposit Pt and Ft alloys onto nanostructured (NS) films composed of perylene red whiskers. The approach has been recently been reviewed by Debe. ... 

---