Pd Single Atom and Cluster Dual Active Sites for Highly Efficient Hydrogenation of Nitroaromatics at Room Temperature and Near Ambient Pressure

Abstract The selective hydrogenation of nitroaromatics to aromatic amines is of great significance in green chemistry and chemical engineering, but mild and efficient hydrogenation remains a challenge. Here we reported a novel catalyst consisting of palladium single atoms (Pd SA ) and palladium clusters (Pd C ) supported on defective TiO 2 (TiO 2 ‐O V ) for highly efficient nitrobenzene hydrogenation to aniline. The 0.20% Pd SA+C /TiO 2 ‐O V achieved a turnover frequency (TOF) of 21154 h −1 under 25 °C and 0.15 MPa, which outperformed most of the reported noble metal‐based catalysts. In situ DRIFTS showed that Pd enhanced ─NO 2 adsorption but the excessive Pd would lead to unnecessary adsorption of the aromatic ring. This work proposed a strategy of developing highly efficient synergistic Pd‐based catalysts for the hydrogenation of a variety of nitroaromatics.