Electrode Kinetics of the Ni Porous Electrode for Hydrogen Production in the Molten Carbonate Electrolysis Cell (MCEC)

2015 ◽  
Vol 66 (3) ◽  
pp. 93-98
Author(s):  
L. Hu ◽  
G. Lindbergh ◽  
C. Lagergren
Keyword(s):  
Hydrogen Production ◽  
Porous Electrode ◽  
Electrolysis Cell ◽  
Electrode Kinetics ◽  
Molten Carbonate ◽  
Kinetics Of

scholarly journals Electrode kinetics of the NiO porous electrode for oxygen production in the molten carbonate electrolysis cell (MCEC)

2015 ◽  
Vol 182 ◽  
pp. 493-509 ◽  
Author(s):  
Lan Hu ◽  
Göran Lindbergh ◽  
Carina Lagergren
Keyword(s):  
Partial Pressure ◽  
Reaction Order ◽  
Porous Electrode ◽  
Exchange Current ◽  
Electrolysis Cell ◽  
Oxygen Production ◽  
Molten Carbonate ◽  
Pressure Dependency ◽  
Low Coverage ◽  
Oxide Ions

The performance of a molten carbonate electrolysis cell (MCEC) is to a great extent determined by the anode, i.e. the oxygen production reaction at the porous NiO electrode. In this study, stationary polarization curves for the NiO electrode were measured under varying gas compositions and temperatures. The exchange current densities were calculated numerically from the slopes at low overpotential. Positive dependency on the exchange current density was found for the partial pressure of oxygen. When the temperature was increased in the range 600–650 °C, the reaction order of oxygen decreased from 0.97 to 0.80. However, there are two different cases for the partial pressure dependency of carbon dioxide within this temperature range: positive values, 0.09–0.30, for the reaction order at lower CO2 concentration, and negative values, −0.26–0.01, with increasing CO2 content. A comparison of theoretically obtained data indicates that the oxygen-producing reaction in MCEC could be reasonably satisfied by the reverse of oxygen reduction by the oxygen mechanism I, an n = 4 electron reaction, assuming a low coverage of oxide ions at high CO2 content and an intermediate coverage for a low CO2 concentration.

Sign in / Sign up

Export Citation Format

Share Document