Synthesis and physicochemical characterization of ZrO2-doped NiMo/Al2O3 nanocatalyst via precipitation and sequential impregnation methods used in hydrodesulfurization of thiophene

摘要

A series of Al2O3-ZrO2 composite with various ZrO2 contents were prepared by precipitation and NiMo was dispersed over them via sequential impregnation. The samples were characterized by XRD, FESEM, EDX, BET, TPR-H-2 and FTIR techniques. XRD patterns indicate the homogeneous dispersion of ZrO2 on Al2O3 in small amounts of ZrO2. Comparison of FESEM images implies that with the incorporation of small amounts of ZrO2 (5, 12 and 17 wt%) on Al2O3, the catalyst morphology changed from large ensembles to smaller particles with uniform distribution. According to TPR-H-2 profiles, adding ZrO2 increases the reducibility of nanocatalysts. Catalytic activity results showed that the NiMo over Al2O3-ZrO2 composite showed higher hydrodesulfurization activity than that of Al2O3 supported catalyst. The maximum of hydrodesulfurization activity was observed for NiMo/Al2O3-ZrO2 nanocatalyst with 12 wt% of ZrO2 content related to enhanced physicochemical properties.