Nested NiPd nanocatalysts fabricated by reactive laser ablation in liquids: A breakthrough in selective nitroarene reduction to anilines

Abstract

The presence of persistent pollutants in water poses a severe environmental threat, driving an urgent need for efficient and eco-friendly remediation strategies. In response, the scientific community is increasingly focused on developing catalytic processes that maximize efficiency while minimizing environmental impact. In this context, we introduce recyclable catalysts based on NiPd nanoparticles (NPs) that feature tunable phase distributions and compositions. By varying Pd doping levels through Reactive Laser Ablation in Liquids (RLAL), we precisely control the catalytic and magnetic properties of these NPs. Notably, a nanocatalyst featuring the NiPd alloyed phase exhibits exceptional catalytic performance, achieving a turnover frequency of 3680 h⁻¹ and 98.5% selectivity in the model transformation of 4-nitrophenol into 4-aminophenol. Additionally, it demonstrates remarkable efficiency in the chemoselective hydrogenation of various nitroarenes to functionalized anilines under mild conditions (atmospheric H₂ pressure, 33 ºC). Furthermore, the synergistic properties arising from the internal structure of these NPs allow them to surpass the performance of nanocatalysts made from their monometallic counterparts and simple mixtures. Overall, this study represents a significant advancement in the precise control of nanocatalyst synthesis and their associated physicochemical properties, paving the way for more efficient redox catalytic protocols, including industrially demanding hydrogenation reactions.