Single and double transition metal atoms doped graphdiyne for highly efficient electrocatalytic reduction of nitric oxide to ammonia

Abstract

The electrocatalytic conversion of nitric oxide (NORR) to ammonia (NH₃) represents a pivotal approach for sustainable energy transformation and efficient waste utilization. Designing highly effective catalysts to facilitate the conversion of NO into NH₃ remains a formidable challenge. In this work, the density functional theory (DFT) is used to design NORR catalysts based on single and double transition metal (TM:Fe, Co, Ni and Cu) atoms supported by graphdiyne (TM@GDY). Among eight catalysts, the Cu₂@GDY is selected as a the most stable NORR catalyst with high NH₃ activity and selectivity. A pivotal discovery underscores that the NORR mechanism is thermodynamically constrained on single atom catalysts (SACs), while being governed by electrochemical processes on double atom catalysts (DACs), a distinction arising from the different d-band centers of these catalysts. Therefore, this work not only introduces an efficient NORR catalyst but also provides crucial insights into the fundamental parameters influencing NORR performance.

Keywords: Ammonia (NH(3)); Density functional theory (DFT); Double atom catalysts (DACs); Nitric oxide (NO); Single atom catalysts (SACs).