Photoinduced Atomic Dispersion of Noble Metal Nanoparticles

The transformation of noble metal nanoparticles into atomically dispersed catalysts has been a long-standing goal to enhance metal utilization and regenerate the activity of agglomerated catalysts. Traditional methods, however, often require high temperatures, specific atmospheres, or complex chemical processes. Here, we present a novel, photoinduced strategy that achieves atomic dispersion of noble metal nanoparticles under ambient conditions. Experimental results and density functional theory (DFT) calculations reveal that chlorine radicals (•Cl) generated during the reaction reduce the electron density around Pd atoms. This, in combination with the attack of •O ₂ ⁻ , facilitates Pd-Pd bond cleavage. The intermediate [PdCl ₄ ] ²⁻ species formed adsorbs onto TiO ₂ via electrostatic interactions and, upon dechlorination, stabilizes into a single-atom Pd ₁ -N ₂ O ₁ structure. This method is applicable to various noble metals (Pd, Pt, Rh) and significantly enhances the catalytic activity of both commercial Pd/C and industrial waste Pd/C catalysts by 17.8-fold and 26-fold, respectively, in the hydrogenation of styrene. This approach offers a simple, green, and sustainable solution for advancing catalytic technologies.