Catalyzing sustainability: phytic acid as a green precursor for metal-free carbon electrocatalysts in ORR

Abstract

The sluggish kinetics and high overpotential of the oxygen reduction reaction (ORR) in fuel cells and metal–air batteries are currently resolved through the use of expensive and scarce platinum-based electrocatalysts. Here, a green and straightforward synthesis method for preparing metal-free phosphorus-doped carbon (PDC) materials via carbonization of phytic acid at temperatures ranging from 700 to 1000 °C is reported. This study provides valuable insights into the effect of carbonization temperature on the surface chemistry and catalytic performance of PDCs. The PDC electrocatalysts exhibit ORR electrocatalytic activity equivalent to that of the state-of-the-art P-doped carbons and show a correlation between the content of C–P species and the electrocatalytic activity for the ORR. The study suggests that C–P-type species are responsible for the improved ORR. These findings not only demonstrate a practical and low-cost approach for preparing highly efficient metal-free electrocatalysts for the ORR, but also highlight their potential for the development of sustainable energy technologies.