Water-induced synthesis of Pd nanotetrahedrons on g-C3N4 for highly efficient hydrogenation of nitroaromatic

g-C3N4 supported Pd nanotetrahedrons (Pd NTs@g-C3N4) are first prepared by an in-situ growth method with water-induced process. The unique Pd nanotetrahedrons with four (111) facets exposed have been prepared by simply varying the dosage of water without the other synthesis condition changed. The optimized Pd NTs@g-C3N4 exhibits higher activity (TOF value: 51462 h−1) toward the hydrogenation of nitrobenzene with respect to the commercial Pd/C. The enhanced activity is attributed to the small size and tetrahedral shape with higher surface energy and more active surface. Most importantly, the Pd NTs@g-C3N4 still shows excellent activity and selectivity for nitrobenzene hydrogenation without obviously deactivation after ten cycles. In addition, the vertical and parallel adsorption behaviors of nitrobenzene molecules on Pd (111) surface are analyzed in detail using the density functional theory (DFT) method, and the interaction mechanism between nitrobenzene and palladium is studied by the charge density difference method.