Converting the redox inactive P-block metal aluminum into active Fenton-like atomically dispersed catalysts to customize singlet oxygen generation

Abstract

Transition-metal-based single-atom catalysts (TM-SACs) are popular for peroxymonosulfate (PMS) conversion into singlet oxygen (¹O₂) in Fenton-like chemistry, however, p-block atomically dispersed metal catalysts have been rarely explored due to the delocalized s/p bands of p-block metals. Herein, guided by theoretical simulations, we have successfully converted a redox inactive p-block metal aluminum (Al) into an active Fenton-like atomically dispersed Al−N₃ catalyst (Al-NC-3) to customize ¹O₂ generation via PMS oxidation. The Al-NC-3 catalyst exhibits fantastic Fenton-like performance and robust stability for bisphenol A (BPA) degradation with a specific activity of 3.03 × 10⁻³ L min⁻¹ m⁻², which is 8.3-fold higher than that of Al−N₄-featured Al-NC-4 counterpart and even comparable to most TM-SACs. The unsaturated Al−N₃ species function as Lewis acid sites enabling directional electron extraction from PMS to initiate PMS oxidation for the exclusive production of ¹O₂. Theoretical calculations reveal that structural alteration from Al−N₄ to Al−N₃ shifts the p-band center of Al closer to the Fermi energy, which enhances the interaction between PMS and Al−N₃ sites and facilitates greater electron transfer from PMS to the AlN₃ moiety, accounting for superior specific activity of Al-NC-3 to Al-NC-4. This work offers useful guidance to design novel Fenton-like SACs for oriented ¹O₂ generation towards environmental applications.