Enhancing alkaline oxygen reduction activity of Fe-N-C single-atom catalysts anchored on a diamond substrate

The development of efficient non-precious metal catalysts for the oxygen reduction reaction (ORR) is crucial for advancing sustainable energy technologies. Although single-atom Fe–N–C materials hold great promise, they are often limited by metal aggregation issues associated with conventional carbon supports. In this study, we propose a novel catalyst design that stabilizes Fe–N–C single-atom sites on a robust diamond-based matrix to fabricate a highly efficient electrocatalyst. With mild graphitization of the diamond surface to enhance its electrical conductivity during electrocatalytic processes, the Fe species are atomically dispersed and form coordinate covalent bonds with pyridinic N. In alkaline electrolyte, the Fe–N–D catalyst exhibits enhanced ORR activity, outperforming both pristine diamond and carbon black reference samples. Density functional theory (DFT) calculations reveal that the active Fe–N 4 –C configuration promotes kinetically efficient ORR by optimizing charge transfer and weakening the O O bond. This work integrates conductive sp 2 ‑carbon with a stable sp 3 -diamond core to establish a novel support for anchoring single-atom catalysts, providing a new substrate materials-design paradigm for electrocatalysis. Download: Download high-res image (124KB) Download: Download full-size image