Synergistic effects of A-site deficiency and anion doping on Pr0.4Sr0.6Ni0.2Fe0.7Mo0.1O3 cathode for H2O electrolysis and CO2 electrolysis

In this work, a strategy of A-site deficiency and F-doping was proposed to prepare Pr0.4Sr0.55Ni0.2Fe0.7-Mo0.1F0.1O2.9 (PSNFMF) cathode. Compared with the reduced Pr0.4Sr0.6Ni0.2Fe0.7Mo0.1O3 (R-PSNFM), the reduced PSNFMF facilitate the exsolution reaction and generate more oxygen vacancies. Moreover, at 800 degrees C, the chemical oxygen surface exchange coefficient (kchem) of R-PSNFMF is 4.31 x 10-4 cm s- 1, 21.8% higher than the value of 3.54 x 10-4 cm s- 1 for R-PSNFM, and the oxygen chemical bulk diffusion coefficient (Dchem) of RPSNFMF is 34.21 x 10-5 cm2 s- 1, 24.3% higher than the value of 27.53 x 10-5 cm2 s- 1 for R-PSNFM, suggesting faster oxygen transport kinetics are obtained for R-PSNFMF. Meanwhile, the synergistic effect of A-site deficiency and anion doping can also promote the electrolysis of H2O and CO2. For H2O electrolysis, the current density of R-PSNFMF based cell at 0.4 V (vs. OCV) is-0.75 A cm-2, 31.6% higher than the value of-0.56 A cm-2 for RPSNFM based cell. And for CO2 electrolysis in harsh condition at 800 degrees C, the current density of R-PSNFMF based cell at 0.4 V (vs. OCV) is-0.43 A cm-2, 38.7% higher than the value of-0.31 A cm-2 for R-PSNFM based cell.

Automated summary

In this study, a strategy of A-site deficiency and F-doping was used to prepare PSNFMF cathode, which exhibited enhanced oxygen transport kinetics and electrolysis performance compared to R-PSNFM. The A-site deficiency and anion doping synergistically promoted the exsolution reaction and increased oxygen vacancies. The current density of R-PSNFMF based cell for H2O electrolysis and CO2 electrolysis was significantly higher than that of R-PSNFM based cell in harsh conditions.