Abstract
The high fuel efficiency of lean-burn engines is associated with high temperature and excess oxygen during combustion and thus is associated with highconcentration NOx emission. This work reveals that very high concentration of NOx in the exhaust can be reduced and hydrocarbons (HCs) can be simultaneously oxidized using a low-temperature solid oxide fuel cell (SOFC). An SOFC unit is constructed with Ni−YSZ as the anode, YSZ as the electrolyte, and La0.6Sr0.4CoO3 (LSC)−Ce0.9Gd0.1O1.95 as the cathode, with or without adding vanadium to LSC. SOFC operation at 450 °C and open circuit can effectively treat NOx over the cathode at a very high concentration in the simulated exhaust. Higher NOx concentration up to 5000 ppm can result in a larger NOx to N2 rate. Moreover, a higher oxygen concentration promotes NO conversion. Complete oxidation of HCs can be achieved by adding silver to the LSC current collecting layer. The SOFCbased emissions control system can treat NOx and HCs simultaneously, and can be operated without consuming the anode fuel (a reductant) at near the engine exhaust temperature to eliminate the need for reductant refilling and extra heating. Doping Cu in B-site at LSC or La deficient to make more vacancies can make Electrochemical-catalytic cells (ECC) have more Electromotive Force (emf) which can make the reation rate (O2 O*+O*) faster. The results show La0.6Sr0.4Co0.9Cu0.1 can effectively treat NOx over the cathode at a very low concentration in the simulated exhaust and La deficient, La0.58Sr0.4Co0.95Cu0.05, can effectively treat NOx over the cathode at a very high concentration in the simulated exhaust. Electrochemical enhancement of NO decomposition occurs when an operating voltage is generated; higher O2 concentration leads to higher enhancement.