制备方法对非负载型Ni-Mo-W催化剂结构和加氢脱硫性能影响的研究

Effects of preparation methods on structure and hydrodesulfurization performance of unsupported Ni-Mo-W catalysts

采用共沉淀法和水热法制备非负载型Ni-Mo-W加氢脱硫催化剂,利用XRD、BET、HRTEM、GC-PFPD表征手段对催化进行表征。结果表明,共沉淀法制备的氧化态催化剂的活性组分具有良好的分散性;水热法制备氧化态催化剂具有较高比表面积、较大孔容、孔径。不同制备方法对硫化态催化剂的晶型结构、比表面积、孔容和孔径影响不大。硫化态催化剂具体较大的比表面积、孔容和孔径,较高的MoS_2和Ni_3S_2晶相堆叠层数。在连续固定高压微反装置上考察了不同制备方法的硫化态催化剂的加氢脱硫活性。结果表明共沉淀法制备的硫化态催化剂的加氢脱硫率高达98.8%,催化剂具有良好的稳定性和催化活性,可持续反应550h。

The unsupported Ni-Mo-W catalysts were prepared by coprecipitat!on and hydrothermal methods and characterized by XRD, BET, HRTEM and GC-PFPD. The results indicated that the oxide catalysts prepared by coprecipitation method have higher metal dispersion, and the oxide catalysts prepared by hydrothermal method have larger specific surface area, pore volume and pore size, however, the preparation methods don＇t obviously affect the crystal type, specific surface area, pore volume and pore size of the sulfurized catalysts. The sulfurized catalysts have larger specific surface area, pore volume and pore size as well as more stacked layers of active component MoS2 and Ni3S2. The hydrodesulfurization activities of the sulfurized catalysts prepared by different methods were investigated in a fixed bed reactor. The results showed that the sulfurized catalyst prepared by coprecipitation could obtain a hydrodesulfurization rate of up to 98.8%, and exhibted well stability and catalytic activity in the continuous reaction of 550 h.