Strong Electronic Orbit Coupling between Cobalt and Single-Atom Praseodymium for Boosted Nitrous Oxide Decomposition on Co 3 O 4 Catalyst.

Nitrous oxide (N 2 O) has gained increasing attention as an important noncarbon dioxide greenhouse gas, and catalytic decomposition is an effective method of reducing its emissions. Here, Co 3 O 4 was synthesized by the sol-gel method and single-atom Pr was confined in its matrix to improve the N 2 O decomposition performance. It was observed that the reaction rate varied in a volcano-like pattern with the amount of doped Pr. A N 2 O decomposition reaction rate 5-7.5 times greater than that of pure Co 3 O 4 is achieved on the catalyst with a Pr/Co molar ratio of 0.06:1, and further Pr doping reduced the activity due to PrO x cluster formation. Combined with X-ray photoelectron spectroscopy, X-ray absorption fine structure, density functional theory and in situ near-ambient pressure X-ray photoelectron spectroscopy, it was demonstrated that the single-atom doped Pr in Co 3 O 4 generates the "Pr 4f-O 2p-Co 3d" network, which redistributes the electrons in Co 3 O 4 lattice and increases the t 2g electrons at the tetracoordinated Co 2+ sites. This coupling between the Pr 4f orbit and Co 2+ 3d orbit triggers the formation of a 4f-3d electronic ladder, which accelerates the electron transfer from Co 2+ to the 3π* antibonding orbital of N 2 O, thus contributing to the N-O bond cleavage. Moreover, the energy barrier for each elementary reaction in the decomposition process of N 2 O is reduced, especially for O 2 desorption. Our work provides a theoretical grounding and reference for designing atomically modified catalysts for N 2 O decomposition.