Electrochemical oxygen

RDT Standard C8-5T, Electrochemical Oxygen Meter for Service in Liquid Sodium, RDT Standards Office, Oak Ridge National Laboratory, Tennessee Pillai, S. R. and Mathews, C. K., J. Nucl. Mater., 137, 107 (1986)... 

M. Stoukides, and C.G. Vayenas, The effect of Electrochemical Oxygen Pumping on the Rate and Selectivity of Ethylene Oxidation on Polycrystalline Silver, J. Catal. 70, 137-146(1981). 

O.A. Mar ina, V.A. Sobyanin, V.D. Belyaev, and V.N. Parmon, The effect of electrochemical oxygen pumping on catalytic properties of Ag and Au electrodes at gas-phase oxidation ofCH4, Catalysis Today 13, 567-570 (1992). 

Figure 8.21. (a) Effect of the rate, I/2F, of electrochemical oxygen ion removal (I<0) on the induced increase in the rate of propylene oxidation on Pt/YSZ.28 (b) Effect of catalyst potential and work function change on the rate enhancement ratio p (=r/r0) at a fixed gaseous composition. Reprinted with permission from Academic Press. 

Figure 8.38. Steady state effect of current on the increase in the rates of ethylene epoxidation (rj) and deep oxidation to CO2 (r2) of C2H4 on Ag and comparison with the rate Go2=I/4F of electrochemical oxygen supply42 pC2H4=l-6 kPa, pO2=10 kPa, T=400°C intrinsic (1=0) selectivity 0.5, Reprinted with permission from Academic Press.

In this work we present results obtained with the YSZ reactor operated in the hatch mode with electrochemical oxygen addition, and with the quartz plug flow reactor operated in the continuous-flow steady-state mode. In the case of continuous flow operation, the molecular sieve trap comprised two packed bed units in parallel in a swing-bed arrangement (Fig. 1), that is, one unit was maintained at low temperature (<70°C) to continuously trap the reactor products while the other was heated for -30 min to 300°C to release the products in a slow stream of He. 

Kinoshita, Kim, Electrochemical Oxygen Technology, Wiley, New York, 1992. 

Kinoshita K. 1992. Electrochemical Oxygen Technology. New York Wiley. 

Fig. 5. Exploded view of an ion-exchange membrane electrochemical oxygen separator. Oxygen removal characteristics of the flow-through type oxygen removal system are shown. Air cathode area = 100 cm2, water temperature = 40 °C.

Various carbon-based catalysts for the electrochemical oxygen reduction have been tested in the air gas-diffusion electrodes [7]. The polarization curves of the air electrodes were measured when operating against an inert electrode in 2 N NaCl-solution. The potential of the air electrodes was measured versus saturated calomel electrode (SCE). 

Kim Kinoshita, Electrochemical oxygen technology, John Willey Sons, Inc. New York, Chichester, Brisbane, Toronto, Singapore. 

Zirconia cells similar to the ones employed in the present study, have been used i) by Mason et al (18) to electrochemically remove oxygen from Pt and Au catalysts used for NO decomposition. It was shown that electrochemical oxygen pumping causes a dramatic increase in the rate of NO decomposition (18,19), ii) by Farr and Vayenas to electrochemically oxidize ammonia and cogenerate NO and electrical energy (20,21), iii) by Vayenas et al (11,12,22,23) to study the mechanism of several metal catalyzed oxidations under open circuit (potentiometric) conditions. 

Figure 3. Transient effect of electrochemical oxygen pumping. Conditions RC 2, Pi X 10-2 bar, P0jt = 9.5 X 10 2 bar, and 400°C.

In this context see also Refs. [83a, 83b]. Comninellis and Plattner [287,287a, 288] have developed a simple method for estimating the facility of the electrochemical oxidation of organic species based on a newly defined electrochemical oxidizability index (EOI) and the degree of oxidation using the electrochemical oxygen demand (EOD). Electrochemical oxidizability index for various benzene derivatives obtained at Pt/Ti and Sn02-ABB-anodes are listed in Table 23. 

K. Kinoshita, Electrochemical Oxygen Technology , John Wiley and Sons, Inc., 1992. 

Basura, V. L, Beattie, P. D. and Holdcroft, S. 1998. Solid-state electrochemical oxygen reduction at Pt —> Nation 117 and Pt —> BAM3G 407 interfaces. Journal ofElectroanalytical Chemistry 458 1-5. 

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