Ti/Ni co-doped perovskite cathode with excellent catalytic activity and CO2 chemisorption ability via nanocatalysts exsolution for solid oxide electrolysis cell

Abstract

Carbon dioxide (CO2) gas is the main cause of global warming and has a significant effect on both climate change and human health. In this study, Ni/Ti co-doped Sr1.95Fe1.2Ni0.1Ti0.2Mo0.5O6-δ (SFNTM) double perovskite oxides were prepared and used as solid oxide electrolysis cell (SOEC) cathode materials for effective CO2 reduction. Ti-doping enhances the structural stability of the cathode material and increases the oxygen vacancy concentration. After treatment in 10% H2/Ar at 800°C, Ni nanoparticles were exsolved in situ on the SFNTM surface (Ni@SFNTM), thereby improving its chemisorption and activation capacity for CO2. Modified by the Ti-doping and the in situ exsolved Ni nanoparticles, the single cell with Ni@SFNMT cathode exhibits improved catalytic activity for CO2 reduction, exhibiting a current density of 2.54 A cm−2 at 1.8 V and 800°C. Furthermore, the single cell shows excellent stability after 100 h at 1.4 V, indicating that Ni/Ti co-doping is an effective strategy for designing novel cathode material with high electrochemical performance for SOEC.