Electrochemical reduction of nitric oxide in different carbon-driven solid state cells

Abstract

A novelty of nitric oxide (NO) abatement technology in a solid state cell has been developed firstly, in which solid carbonaceous materials instead of gas (eg., H2 or CH4 etc.) work as reductant and fuel. The configuration of anode-supported nickel-yttrial stablized zirconia (Ni-YSZ), YSZ (yttrial stablized zirconia) electrolyte, LSM-YSZ (lanthanum strontium manganite-yttrial stablized zirconia) cathode, was fabricated into tubular cell with 13 mm in length and inner diameters 5 mm. Three carbonaceous materials, including activated carbon (AC), carbon black (BC) and graphite (GC), were investigated with regard to specific area, functional group, thermal activity and morphology by means of N2-BET, FT-IR, TG and SEM, respectively. NO conversion efficiency in excess of 85% can be achieved in the solid state cells driven by AC at 800 °C, higher than cells by BC and GC. BC is one of cheaper carbonaceous material substituting for AC in NO electrochemical reduction, due to its comparable performance. Higher specific area (1745 m2 g−1) and higher content of oxygen-containing functional groups assigned to AC contributes to the better electrochemical behaviours evidenced by AC impedance spectra. Similar thermal activities can be observed both for AC and BC. This novel configuration offers a low-risk, inexpensive and highly-efficient option applicable to purification of exhausts from diesel or gasoline engine.