Ruthenium electrodes

Petrii OA, Podlovchenko BI, Fiumkin AN, Hira-Lal. 1965. The behaviour of platinized-platinum and platinum-ruthenium electrodes in methanol solutions. J Electroanal Chem 10 253-269. 

Figure 4-1 is a voitammogram of ruthenium deposited chemically on a platinum wire, in 3 M sulfuric add. It seems that the deposition was thick enough to cover the surface totally because there are no features of platinTun. Therefore, the voitammogram provides for a pure ruthenium electrode. 

CO (6). Another approach is to develop a CO tolerant anode catalyst such as the platinum/ruthenium electrodes currently under consideration. Platinum/ruthenium anodes have allowed the cells to operate, with a low level air bleed, for over 3,000 continuous hours on reformate fuel containing 10 ppm CO (23). 

Improvements in solid polymer electrolyte materials have extended the operating temperatures of direct methanol PEFCs from 60 C to almost 100 C. Electrocatalyst developments have focused on materials that have higher intrinsic activity. Researchers at the University of Newcastle upon Tyne have reported over 200 mA/cm at 0.3 V at 80 C with platinum/ruthenium electrodes having platinum loading of 3.0 mg/cm. The Jet Propulsion Laboratory in the U.S. has reported over 100 mA/cm at 0.4 V at 60 C with platinum loading of 0.5 mg/cm. Recent work at Johnson Matthey has clearly shown that platinum/ruthenium materials possess substantially higher intrinsic activity than platinum alone (45). 

Fig. 18.9. (A) Schematic presentation of biotinylated polypyrrole-ruthenium electrode in presence of an oxidative quencher and the resulting photocurrent response by switching the excitation light on and off. (B) Reduced photocurrent response and schematic presentation of the polypyrrole-ruthenium electrode after incubation in anti-cholera toxin solution.

Ren, B., Lin, X.F., Yang, Z.L. et al. (2003) Surface-enhanced Raman scattering in the ultraviolet spectral region UV-SERS on rhodium and ruthenium electrodes. Journal of the American Chemical Society, 125, 9598-9599. 

Hadzi-Jordanov S, Angerstein-Kozlowska H, Conway BE (1975) Surface oxidation and H deposition at ruthenium electrodes Resolution of component processes in potential-sweep experiments. J Electroanal Chem Interfacial Electrochem 60 359-362... 

Hadzi-Jordanov, S. Angerstein-Kozlowska, H. Vukovic, M. Conway, B. E. Reversibility and Growth Behavior of Surface Oxide Films at Ruthenium Electrodes. J. Electrochem. Soc. 1978, 125, 1471. 

Hadzi-Jordanov S, Angerstein-Kozlowska H, Vukovic M, Conway BE (1977) The state of electrodeposited hydrogen at ruthenium electrodes. J Phys Chem 81 2271-2279... 

Vukovic M, Angerstein-Kozlowska H, Conway BE (1982) Electrocatalytic activatimi of ruthenium electrodes Jot the CI2 and O2 evolution reactions by anodic/cathodic cycling. J Appl Electrochem 12 193-204... 

Vukovic M, Valla T.MilunM (1993) Electron spectroscopy characterization of an activated ruthenium electrode. J Electroanal Chem 356 81—91... 

Figure 3-6 shows that performance equivalent to that obtained on pure hydrogen can be achieved using this approach. It is assumed that this approach would also apply to reformed natural gas that incorporate water gas shift to obtain CO levels of 1% entering the fuel cell. This approach results in a loss of fuel, that should not exceed 4 percent provided the reformed fuel gas can be limited to 1 percent CO(l). Another approach is to develop a CO-tolerant anode catalyst such as the platinum/ruthenium electrodes currently under consideration. Platinum/ruthenium anodes have allowed cells to operate, with a low-level air bleed, for over 3,000 continuous hours on reformate fuel containing 10 ppm CO (27). 

Figure 3.1. Electrochemical behaviors of various noble metal electrodes in sulfuric acid [23-26]. (Graphs (a) (c) reprinted from Journal of Electroanatytical Chemistry, 35, Rand DAJ, Woods R, A study of the dissolution of platinum, palladium, rhodium and gold electrodes in 1 M sulphuric acid by cyclic voltammetry, 209-18, 1972 (b) reprinted from J Electroanal Chem, 55(3), Rand DAJ, Woods R, Cyclic voltammetric studies on iridium electrodes in sulphuric acid solutions nature of oxygen layer and metal dissolution, 375-81, 1974 (d) reprinted from J Electroanal Chem, 89(1), Michell D, Rand DAJ, Woods R, A study of ruthenium electrodes by cyclic voltammetry and X-ray emission spectroscopy, 11-27, 1978 (e) reprinted from J Electroanal Chem, 39(2), Capon A, Parsons R, The effect of strong acid on the reactions of hydrogen and oxygen on the noble metals. A study using cyclic voltammetry and a new teflon electrode holder, 275-86, 1972, all with permission from Elsevier.)...

Michell D, Rand DAJ, Woods R. A study of ruthenium electrodes by cyclic voltammetry and X-ray emission spectroscopy. J Electroanal Chem 1978 89(1) 11-27. Capon A, Parsons R. The effect of strong acid on the reactions of hydrogen and oxygen on the noble metals. A study using cyclic voltammetry and a new teflon electrode holder. J Electroanal Chem 1972 39(2) 275-86. 

Entina VS, Petry OA. Methanol electro-oxidation on platinum+ruthenium and ruthenium electrodes at various temperatures. Elektrokhimi 1968 4 678-81. 

Park K-W, Sung Y-E. Catalytic activity of platinum on ruthenium electrodes with modified (electro)chemical states. J Phys Chem B 2005 109 13585-9. 

Petiii and Entina [150,180] investigated the electrochemical oxidation of methanol on a platinum— ruthenium electrode in detail. On a clean surface the process is determined by dehydrogenation of methanol, and under stationary conditions by the oxidation of methanol adsorption products with participation of OH kinetic relationships governing the process on the platinum - ruthenium electrode are fovmd to be simpler Hian on the Pt /Pt electrode. In particular, the equations... 

---