3D二硫化钼/石墨烯组装体的制备及其催化脱硫性能

Fabrication of three-dimensional MoS_2-graphene hybrid monoliths and their catalytic performance for hydrodesulfurization

采用水热合成法,原位一步还原硫钼酸铵/氧化石墨前驱体,得到三维的二硫化钼/石墨烯(3D-MoS2/G)组装体催化剂。通过X-射线衍射仪、傅里叶变换红外光谱仪、拉曼光谱仪、场发射扫描电镜、透射电镜以及低温氮吸附等手段对其结构和形貌进行表征。以羰基硫(COS)的催化加氢转化为评价指标,对比研究微波处理前/后组装体催化剂的加氢脱硫性能。与传统硫化法制备的MoS2/γ-Al2O3催化剂相比,经微波处理的水热一步法构筑的3D-MoS2/G-160M组装体显示出优异的催化加氢脱硫活性,在较低的反应温度下(260℃),COS转化率即可达100%。这种优异的催化性能归结为三维组装体的特殊结构及高度分散在其石墨烯片层上的MoS2纳米晶的共同作用。

A simple process to synthesize three-dimensional molybdenum disulfide-graphene monolithic catalysts （3D-MoS2-G） was developed. 3D-MoS2-G hybrid monoliths were fabricated by a combined hydrothermal self-assembly and freeze-drying treat- ment, in which ammonium tetrathiomolybdate and graphite oxide were used as starting materials. The structure and morphology of the samples were characterized by X-ray diffraction, Fourier transform infrared spectrometry, Raman spectrometry, field emission scanning electron microscopy, transmission electron microscopy and nitrogen adsorption. The catalytic performance of the hybrid monoliths was investigated by evaluating the activity for the hydrodesulfurization （ HDS ） of carbonyl sulfide （COS）. In addition, the influence of microwave irradiation on the catalytic property of the 3D-MoS2-G monoliths was also investigated. It is demonstra- ted that after microwave irradiation the 3D-MoS2-G monoliths show an excellent activity for COS hydrogenation compared with the traditional MoS2/γ-Al2O3 catalyst prepared by impregnation-sulfidation. The 3D-MoS2-G-160M monolith hydrothermally synthe- sized at 160℃ exhibits the highest COS conversion of 100% at a relatively low temperature （260℃） for the HDS reaction. The su- perior performance of the 3D-MoS2-G-160M catalyst can be ascribed to the unique hybridized structure of the MoS2 nanoparticles u- niformly dispersed on graphene sheets in the monolith.