A solid oxide fuel cell (SOFC) unit, operating at 800-875 degrees C, is constructed with Ni-(Ce,Gd)O2-x (GDC) as the anode, yttria-stabilized zirconia as the electrolyte, and V2O5-added (LaSr)(CoFe)O-3-GDC as the cathode. Both the current-voltage measurement and the fixed-voltage test were performed on electrochemical NO reduction, i.e. DeNO(x) with power generation. As the voltage decreases, the NO conversion increases but only slightly. DeNO(x) by SOFC is operational with the O-2 concentration of 2-5% and temperature of 800-875 degrees C. The NO conversion increases with decreasing O-2 and NO concentrations but with increasing temperature. This process of DeNO(x) by SOFC should be suitable for NO removal from the exhaust of lean burn engines. (C) 2010 Elsevier B.V. All rights reserved.