Abstract:

MoS₂ catalysts supported on reduced graphene oxide (MoS₂/rGO) were synthesized through hydrothermal process. The nanostructure parameters including stacking layers, slab length, and dispersion were characterized by scanning electron microscopy with energy dispersive X-ray spectroscopy, X-ray diffraction, Raman spectroscopy and high-resolution transmission electron microscopy. The results indicated that the hydrothermal synthesis method could successfully load MoS₂ over the surface of rGO support, and adjust the catalytic active sites of MoS₂ by tuning the Mo precursors. Polycyclic aromatic hydrocarbon anthracene was used as the model compound of heavy oils to evaluate the catalytic hydrogenation performance of the MoS₂/rGO catalysts. The MoS₂/rGO-ATTM catalyst, synthesized with ammonium tetrathiomolybdate as Mo precursor by the hydrothermal method, demonstrated an extremely high anthracene hydrogenation conversion of 55.1% and a high selectivity to octahydroanthracene of 86.6%, which were respectively 2.0 times and 4.2 times as high as those of the IM-MoS₂/rGO catalyst synthesized by impregnation method. The catalytic hydrogenation activities of MoS₂/rGO catalysts were not related to their surface area, but depended on their stacking layers and slab lengths. The excellent catalytic activity of the MoS₂/rGO-ATTM catalyst may be ascribed to the high exposure of hydrogenation active sites, the enhanced dispersion of MoS₂ nanosheets in the catalyst, and the good suspension of the catalyst in the reaction mixture.

Key words: molybdenum disulfide(MoS₂), reduced graphene oxide, hydrothermal, catalyst, catalytic hydrogenation

摘要：

采用水热法制备了一系列还原氧化石墨烯（rGO）负载的MoS₂催化剂（MoS₂/rGO）。通过SEM、XRD、EDX、拉曼光谱、HRTEM等手段表征了不同钼源制备的MoS₂/rGO催化剂中MoS₂的堆积层数、片层尺寸、分散性等纳米结构。表征结果显示水热法可以成功地将MoS₂高分散、均匀地负载在rGO表面，且可以通过调控钼源种类调变MoS₂/rGO催化剂中MoS₂催化加氢活性位。采用蒽作为重质油模型化合物评价了MoS₂/rGO催化剂的催化加氢性能，结果表明以四硫代钼酸铵为钼源水热法制备的MoS₂/rGO-ATTM催化剂蒽加氢率和八氢蒽选择性分别是浸渍法制备IM-MoS₂/rGO催化剂的2.0倍和4.2倍。MoS₂/rGO催化剂的催化加氢活性与比表面积无关，主要取决于其上MoS₂纳米片的堆积层数和片层长度。MoS₂/rGO-ATTM催化剂的高催化加氢活性可以归结于其上MoS₂纳米片的高催化加氢活性位暴露量、催化剂的高分散性和高悬浮性。

关键词: 二硫化钼, 还原氧化石墨烯, 水热, 催化剂, 催化加氢