Computational Engineering of Non-van der Waals 2D Magnetene for Enhanced Oxygen Evolution and Reduction Reactions.

Non-van der Waals two-dimensional materials containing exposed transition metal atoms are promising catalysts for green energy storage and conversion. For instance, hematene and ilmenene have been successfully applied as catalysts. Building on these reports, this work is the first investigation of recently synthesized magnetene towards the Oxygen Evolution Reaction (OER) and Oxygen Reduction Reaction (ORR). Using Density Functional Theory (DFT) calculations, we unveil the mechanism, performance and ideal conditions for OER and ORR on magnetene. With overpotentials of η=0.50 V and η=0.41 V, the material is not only a bifunctional catalyst, but also superior to state-of-the-art systems such as Pt and IrO. Additionally, its catalytic properties can be further enhanced through engineering strategies such as point defects and in-plane compression. It reaches η=0.28 V at a compressive strain of only 2 %, while the presence of Ni boosts it to η=0.39 V and η=0.31 V, comparable to many reported single-atom catalysts. Overall, this work demonstrates that magnetene is a promising bifunctional catalyst for applications such as regenerative fuel cells and metal-air batteries.