摘要
•Acid-resistant transition metals (Mn, Sn, and Sb) modify Co3O4's electrocatalytic properties.•Mn integrates smoothly into Co3O4; Sn and Sb modify surface chemistry, altering the Co2+/Co3+ ratio.•The Sn-Co3O4 variant shows compelling OER activity and durability.•Proven durability in PEMWE cells, maintaining performance at 100 mA/cm2 and 80 °C for over 120 h.
Spinel cobalt oxide (Co3O4) is a promising, cost-effective, and precious group metal (PGM)-free alternative to iridium-based catalysts for the oxygen evolution reaction (OER) in polymer electrolyte membrane water electrolyzers (PEMWE). However, its application is limited by poor stability under acidic conditions. This study tackles this issue by modifying Co3O4 with acid-resistant elements including tin (Sn), antimony (Sb), and manganese (Mn). Advanced characterization methods were employed to decipher the structure-property relationships of the hydrothermally synthesized catalyst materials. The modified Co3O4 catalysts were thoroughly tested for their OER performance, where the tin-modified Sn-Co3O4 exhibited the highest activity and stability in aqueous acidic electrolytes. Successful integration in a practical PEM water electrolysis cell is demonstrated, delivering a current density over 100 mA/cm2. Our results show notable improvements in both the performance and durability of the Co3O4 spinel catalysts, which is attributed to the promoting effect of the stable Sn-oxide promoters.
This study outlines the groundbreaking exploration into enhancing spinel cobalt oxide's electrocatalytic properties through the strategic addition of stable transition metals. Utilizing hydrothermal synthesis, the nuanced effects of metal incorporation on structural and catalytic behaviors are unveiled. Our study particularly focuses on the elemental integration's impact on grain size, surface chemistry, and the oxygen evolution reaction, leading to improved performance in proton exchange membrane water electrolysis cells. [Display omitted]