Application of Electrochemical Cell to Practical deNO_x Reactor

抄録

Electrochemical cells can be applied to not only fuel cells and oxygen sensors but also oxidation/reduction reactors. One of the applications is deNOx cell, which can reduce NOx to N₂ without any reducing agents. Conventional cells without selective electrode have decomposed co-existing O₂ in preference to NOx, resulting in an extremely low efficiency and an impracticable high electric power.We have investigated a selective electrode that prefers to reduce NOx in the presence of O₂.The electrode consisted of two layers, NiO+YSZ|Pt+YSZ|YSZ(electrolyte). The deNOx performance was about 4.0x10^-4 mg/s•cm² (90mW/cm²). On the basis of the results of the above experimental cell with 20mm diameter-size, we fabricated a practical deNOx cell with 100x100 mm size. The deNOx cell consisted of NiO+YSZ|Pt+YSZ(cathode)|electrolyte|LSM+YSZ(anode). We also designed a stack with about 20 cells for the practical application.Research supported by NEDO, under the Synergy Ceramics Project promoted by METI, Japan.