Two-Dimensional Pd Nanosheets with Enhanced Catalytic Activity for Selective Hydrogenation of Nitrobenzene to Aniline
Jiashi Wang, Ce Du, Qinhong Wei, Wenzhong Shen
Abstract
Two-dimensional (2D) metallic Pd nanosheets were synthesized by an ion-exchange method using PdCl42– and magnesium- and aluminum-based metallic (LDH) as intercalation ion and host material, respectively. The LDH-supported Pd catalyst (Pd/LDH) presented two kinds of existing forms of Pd species comprising Pd nanosheets and nanoparticles. Characterizations by FT-IR spectra and HAADF-STEM images revealed that the Pd nanosheets were intercalated into the sandwich layer of hydrotalcite. The Pd/LDH catalyst was probed for the catalytic hydrogenation of nitrobenzene to aniline, and the Pd/LDH catalyst exhibited excellent catalytic activity with a high TOF value of 133.8 h–1, much higher than that of 97.3 h–1 on LDH-supported Pd nanoparticles catalyst. The results indicated that the catalytic activity of the formed Pd nanosheets was far higher than that of Pd nanoparticles. The edges of 2D Pd nanosheets, due to its negatively electronic property as well as unsaturated coordination, could be the main reason for the enhanced catalytic hydrogenation.