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

Abstract

In this work, a strategy of A-site deficiency and F-doping was proposed to prepare Pr0.4Sr0.55Ni0.2Fe0.7Mo0.1F0.1O2.9 (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 °C, the chemical oxygen surface exchange coefficient (kchem) of R-PSNFMF is 4.31 × 10−4 cm s−1, 21.8% higher than the value of 3.54 × 10−4 cm s−1 for R-PSNFM, and the oxygen chemical bulk diffusion coefficient (Dchem) of R-PSNFMF is 34.21 × 10−5 cm2 s−1, 24.3% higher than the value of 27.53 × 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 R-PSNFM based cell. And for CO2 electrolysis in harsh condition at 800 °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.