Accelerating Net Zero chemical manufacturing series: investment in low-carbon infrastructure will play a major role

Abstract

Sr- and Mo-deficiency Sr1.95TiMo1−xO6–δ (STM1−xO; x = 0–0.075) double perovskites are prepared and applied as potential anodes for solid-oxide fuel cells (SOFCs) operated in sulfur-containing syngas. The effect of Sr- and Mo- deficiency on the crystalline nature, electrical and thermal properties and electrochemical performance are investigated. The STM0.925O crystallizes in a single-phase cubic perovskite structure and has excellent thermal and chemical compatibilities with Ce0.9Gd0.1O1.95, Ce0.8Sm0.2O1.9 and La0.9Sr0.1Ga0.8Mg0.2O3–δ electrolytes. The conductivities of STM0.925O in H2 at 550 °C–850 °C are higher than 160 S cm−1. The polarization resistance (Rp) of STM0.925O is recorded as 1.451 Ω cm2 at 850 °C in H2, which is 51% lower than that in pristine Sr2TiMoO6, and the maximum power density (Pmax) at 800 °C in H2 shows 41% increment as compared to Sr2TiMoO6. The electrochemical performance of STM0.925O is further enhanced by impregnation of Pd: the Rp is decreased from 0.73 Ω cm2 to 0.33 Ω cm2 for STM0.925O and Pd-impregnated STM0.925O (Pd-STM0.925O) anodes, while the corresponding Pmax in H2 increased from 649 to 1051 mW cm−2 at 850 °C. The Pd-STM0.925O shows high electrochemical property and durability in simulated coal syngas containing sulfur (3% H2O), making it a promising anode for hydrocarbon-fueled SOFCs.