دانشگاه صنعتی سهند
عنوان مقاله [English]
In oil refining industries, sulfur in the petroleum derivatives is removed by a hydrodesulfurization process. In general, the traditional hydrodesulfurization catalysts are CoMo/Al2O3 and NiMo/Al2O3. Addition of secondary promoter, phosphorus, is proposed as useful solution for increasing catalyst activity and production of standard fuels. In this research, a series of NiMoP/Al2O3 nanocatalysts with different loadings of phosphorus were synthesised with impregnation method and was evaluated for catalytic hydrodesulfurization (HDS) of thiophene (as a model sulfur component) in the atmospheric pressure. The synthesized nanocatalysts were characterized by XRD, FESEM, BET and FTIR techniques. The XRD results confirmed high dispersion of particles on the surface of γ-Al2O3 support. The FESEM images showed destroying of agglomerate and appropriate distribution of nanocatalyst particles due to application of optimal level of phosphorus. The specific surface area of the samples was decreased with increasing phosphorus content. The FTIR analysis revealed that the use of phosphorus promoter increased the distribution of the active phase, generated more active sites and decreased production of nickel spinel. The results of the catalytic activity for thiophene HDS reaction indicated that the synthesized nanocatalyst with phosphorus content of 0.8 wt% had the highest activity and was able to remove thiophene from the initial solution to less than 100 ppm. These results could be addressed by increasing acidity and excellent structural properties of the NiMoP/Al2O3 nanocatalyst with phosphorus loading.