Non-precious metal activated MoSi2N4 monolayers for high-performance OER and ORR electrocatalysts: A first-principles study

Developing high-performance electrocatalysts for oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) is crucial for energy conversion and storage. Recently, a new type of two-dimensional material MoSi2N4 was successfully synthesized and received considerable attention because of novel properties and potential applications. Herein, by means of first principles calculation, the OER/ORR activities of 3d transition metal (TM) atoms embedded MoSi2N4 (TM@MSN) were investigated. The calculated results indicate that TM atoms on MoSi2N4 exhibit good electrochemical stability. On TM sites, Ti@MSN shows the highest OER activity with an overpotential of 0.48 V, whereas Cr@MSN is the most active ORR catalyst with an overpotential of 0.48 V. The Si site (Si-N1-Cu) of Cu@MSN follows the dual-site mechanism, exhibiting the same OER/ORR overpotential as that of N site (0.55/0.65 V). Interestingly, the outer N site (Zn-N1) of Zn@MSN achieves the lowest OER overpotential of 0.38 V, better than that of the state-of-the-art RuO2 catalyst. We demonstrate that 3d TM atoms not only serve as active sites themselves but also activate the host atoms to improve OER/ORR performance of MoSi2N4. Our work opens new windows of opportunity for developing novel catalysts beyond the precious metal-based electrocatalysts for efficient energy conversion and storage.

Automated summary

This study focuses on investigating the OER/ORR activities of 3d transition metal atoms embedded MoSi2N4, with Ti and Cr showing the best performance as OER and ORR catalysts, while different sites of Cu and Zn also exhibit good electrocatalytic properties in the system.