Removal of nitrogen oxide by steam electrolysis cell with proton conducting ceramics and a Co/Al2O3 catalyst

Steam electrolysis cells were constructed using proton conducting ceramics SrCe0.95Yb0.05O3-alpha, and SrZr0.9 Yb0.1O3-alpha as electrolytes. The remo val of nitrogen oxide (NO) by the hydrogen produced by steam electrolysis c ells was examined. When a Co/Al2O3 catalyst was set on the cathode of the c ell, NO was effectively removed even in excess O-2. A cell with a SrCe0.95Y b0.95O3-alpha electrolyte and a Co/Al2O3 catalyst could remove NO with abou t 100% efficiency in N-2 containing 8% O-2 and 1000 ppm NO at 440 degrees C . On the other hand, the removal efficiency of NO for only a Co/Al2O3 catal yst was less than 4% under the same conditions. It was found that the steam electrolysis cell in combination with a Co/Al2O3 catalyst was very effecti ve for the removal of NO in excess O-2.