Tuning exsolution of nanoparticles in defect engineered layered perovskite oxides for efficient CO2 electrolysis

Solid oxide electrolysis cell (SOEC) could be a potential technology to afford chemical storage of renew-able electricity by converting water and carbon dioxide. In this work, we present the Ni-doped layered perovskite oxides, (La4Srn_4)0.9Ti0.9nNi0.1nO3n+2 with n = 5, 8, and 12 (LSTNn) for application as catalysts of CO2 electrolysis with the exsolution of Ni nanoparticles through a simple in-situ growth method. It is found that the density, size, and distribution of exsolved Ni nanoparticles are determined by the num-ber of n in LSTNn due to the different stack structures of TiO6 octahedra along the c axis. The Ni doping in LSTNn significantly improved the electrochemical activity by increasing oxygen vacancies, and the Ni metallic nanoparticles afford much more active sites. The results show that LSTNn cathodes can success-fully be manipulated the activity by controlling both the n number and Ni exsolution. Among these LSTNn (n = 5, 8, and 12), LSTN8 renders a higher activity for electrolysis of CO2 with a current density of 1.50A cm_2@2.0 V at 800 & DEG;C It is clear from these results that the number of n in (La4Srn_4)0.9Ti0.9nNi0.1nO3n+2 with Ni-doping is a key factor in controlling the electrochemical performance and catalytic activity in SOEC.& COPY; 2023 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.

Automated summary

In this study, Ni-doped layered perovskite oxides (La4Srn_4)0.9Ti0.9nNi0.1nO3n+2 with different values of n (5, 8, and 12) were investigated as catalysts for CO2 electrolysis. It was found that Ni doping significantly enhanced the electrochemical activity by increasing oxygen vacancies and providing more active sites. The results showed that the activity of the LSTNn cathodes could be manipulated by controlling the n number and Ni exsolution, with LSTN8 demonstrating the highest activity for CO2 electrolysis at 800℃ and 2.0 V.