Efficient urea photosynthesis via CuFe dual-atom synergistic catalysis

Abstract

Photocatalytic conversion of N₂ and CO₂ into urea is a highly desirable yet formidable challenge given the inherent inertness of N₂/CO₂ and poor C–N coupling activity. Herein, we introduce a Cu single-atom-decorated porous Fe₂O₃ nanorod (Cu-Fe₂O₃) photocatalyst with a Cu–O–Fe configuration for efficient photocatalytic N₂/CO₂ co-reduction to urea. Because the d-orbitals of the Cu/Fe sites are close to the molecular orbitals of CO₂/N₂, the CuFe dual active sites can selectively adsorb and activate N₂/CO₂, thereby facilitating efficient C–N coupling. The incorporation of the high-electrostatic-potential Cu creates a localized electrostatic-potential difference over Fe₂O₃, enabling the sequential activation of CO₂ and N₂. Consequently, Cu-Fe₂O₃ offers the highest urea activity (171 ± 12 μmol g⁻¹ h⁻¹) and selectivity (>90%) reported to date. This work showcases a promising avenue for green urea synthesis as well as the asymmetric coupling reaction.