The present study focuses on the comparison of Ni-GDC cathodes fabricated by the mechanical mixing (MM) and the spray pyrolysis (SP) methods toward the reduction of CO2 on solid oxide electrolysis cells (SOECs). The synthesized powders are characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The short-term performance and stability of each cathode are measured during the galvanostatic experiment at -1.20 A cm(-2) and 1000 degrees C. A relatively better performance and improved stability have been achieved for the cathode fabricated by SP method, which was supported by the pre- and post-test microstructural analyses. At the same time, effects of preparation methods on the triple phase boundary (TPB) length, two-phase boundary (contact area fraction of active GDC/pore), and isolated phase ratio are also evaluated from the focused ion beam-scanning electron microscope (FIB-SEM) tomography. The computed tomography results reveal that the cathode prepared by SP has larger TPB length and two-phase-boundary as compared with the one prepared by MM, which will be the one of the reasons for the better performance of the cell with Ni-GDC cathode prepared by SP. (C) 2016 The Electrochemical Society. All rights reserved.