Microemulsion-mediated hydrothermal synthesis of flower-like MoS2 nanomaterials with enhanced catalytic activities for anthracene hydrogenation

Flower-like intercalated MoS 2 nanomaterials have been successfully synthesized via a microemulsionmediated hydrothermal (MMH) method, and characterized by X-ray diffraction, Raman spectroscopy, element analysis, scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis, and Fourier transform infrared spectroscopy in detail. Their catalytic performance for anthracene hydrogenation was evaluated using a slurry-bed batch reactor with an initial hydrogen pressure of 80 bar at 350 °C for 4 h. The intercalated MoS 2 nanoflowers synthesized from Na 2 MoO 4 (MoS 2 -S) and H 2 MoO 4 (MoS 2 -A) as molybdenum precursors have diameters of about 150 and 50 nm, respectively. MoS 2 nanosheets on MoS 2 -S and MoS 2 -A possess stacking layer numbers of 5–10 and 2–5, and slab lengths of about 15 and 10 nm, respectively. The interlayer distances of MoS 2 -S and MoS 2 -A are both enlarged from 0.62 nm to about 0.95 nm due to the intercalation of NH4 + and surfactant molecules. The MoS 2 nanoflowers have high catalytic activities for anthracene hydrogenation. The selectivity for octahydroanthracene, a deeply hydrogenated product, over MoS 2 -A is 89.8%, which is 31.0 times higher than that over commercial bulk MoS 2 . Fully hydrogenated product (perhydroanthracene) was also detected over MoS 2 nanoflowers with a selectivity of 3.7%. The enhanced hydrogenation activities of MoS 2 nanoflowers can be ascribed to the high exposure of catalytic active sites, resulting from the smaller particle size, fewer stacking layer, shorter slab length and enlarged interlayer distance of MoS 2 nanoflowers compared with commercial bulk MoS 2 . In addition, a possible growth mechanism of MoS 2 nanoflowers synthesized via the MMH method was proposed.