水热法制备高活性的纳米MoS2催化剂

摘要

采用水热法直接制备了Co/Ni促进的纳米MoS2催化剂,利用XRD,SEM,EDX-mapping和HRTEM方法对催化剂进行表征,并以二苯并噻吩(DBT)为模型化合物考察了加氢脱硫(HDS)性能.表征结果显示,该催化剂由纳米片层堆积而成,为典型的MoS2结构,纳米片尺寸约为5nm,堆积度为1～2层,助剂元素均匀分布于MoS2中.催化剂直接用于催化DBT的HDS反应具有较高的活性,原料中n(Co)∶n(Co+Mo) =0.3的催化剂活性最高,DBT转化率达到75.8％.催化剂在H2和H2/H2S氛围中热处理后,晶化度提高,活性位点数减少,HDS活性降低.添加Co助剂的催化剂的活性优于添加Ni助剂的催化剂.%Co/Ni promoted MoS2 nano-catalysts were synthesized by hydrothermal method directly and characterized by XRD,SEM,EDX-mapping and HRTEM.hydrodesulfurization(HDS) performances of catalysts were evaluated by using dibenzothiophene(DBT) as model compound.The results showed that the catalysts were built by nanosheets,which were typical structure of MoS2.The slab lengths of nanosheets were about 5 nm and stacking layer numbers were 1-2.The promoted elements distributed in MoS2 evenly.As-synthesized catalysts had high activity when used to catalyze HDS reaction of DBT directly.When the atomic ratio of Co to (Co+Mo) was 0.3 in the raw materials,the conversion of dibenzothiophene achieved the highest to 75.8％.After heat treatment under H2 or H2/H2S atmospheres,the crystallization degree of catalysts was enhanced and the amount of active sites decreased,which resulted in the decrease of HDS activity.Co-promoted catalysts had higher activity than Ni-promoted catalysts.