Enhanced\nCarbon Dioxide Electrolysis in Zr-Doped Ceria

In solid oxide electrolysis cells (SOECs), the ionic\nconductivity\nof the electrode significantly affects the polarization resistance.\nTherefore, enhancing the ionic conductivity can effectively optimize\nthe performance. In this study, we select cerium oxide, which is known\nfor its excellent redox properties and ability to disperse metal nanoparticles,\nand we incorporated Zr ions to significantly improve its ionic conductivity.\nThe experimental results indicate that the cathode polarization resistance\nof a symmetric cell using Ce<sub>0.85</sub>Zr<sub>0.15</sub>O<sub>2</sub> cathode material is 0.085 Ω cm<sup>–2</sup> at\n850 °C and 1.8 V. Furthermore, the Ce<sub>0.85</sub>Zr<sub>0.15</sub>O<sub>2</sub> cathode exhibits a current density of 0.78 A cm<sup>–2</sup>, which is markedly higher than that of the CeO<sub>2</sub> SOEC (0.45 A cm<sup>–2</sup>). The Ce<sub>0.85</sub>Zr<sub>0.15</sub>O<sub>2</sub> cathode also achieves a CO yield of\n5.4 mL cm<sup>–2</sup> min<sup>–1</sup>, which is considerably\nhigher than that of the pure CeO<sub>2</sub> cathode. Incorporating\nZr ions into CeO<sub>2</sub> enhances the ionic conductivity, reduces\nthe cathode polarization resistance, and improves the electrochemical\nperformance and catalytic efficiency of SOECs. Thus, this study demonstrates\nthe effectiveness of Zr ion doping in enhancing the ionic conductivity\nof cerium oxide.