Impedance studies on LSCMGDC cathode for high temperature CO _2 electrolysis

摘要

The cathode performance of LSCMGDC composite for high temperature CO _2 electrolysis has been studied by electrochemical impedance spectroscopy (EIS) measurements in a three-electrode electrolysis cell using Pt paste as current collector. The main feature of LSCMGDC cathode is that it showed a Gerischer like impedance dispersion at 900°C in all CO _2-CO mixtures investigated here. With increasing CO concentration and operating potential, the Rs changes little whilst, the Rp declines markedly for LSCMGDC composite cathode. The surface adsorptiondesorption equilibration andor surface diffusion processes play a dominant role in the electrochemical reduction of CO _2 by SOEC.