Promoting effect of the addition of citric acid on Co-MoS₂/β-Al₂O₃ catalysts for the HDS of thiophene

抄録

The effect of the addition of citric acid was investigated for a series of Co-MoS₂/β-Al₂O₃ catalysts containing various amounts of boron (0-4.7 wt.%) prepared by a CVD technique using Co(CO)₃NO as a precursor of Co. The catalysts were characterized by means of NO Adsorption and Raman Spectroscopy. The HDS activity of the catalyst was significantly increased by the addition of citric acid and remain constant at a higher boron content (>0.9 wt.%). However, effect of citric acid addition did not change the TOF on the Co-Mo-S phase. It seems that, the addition of citric acid only increase the dispersion of Mo oxides on the support. Moreover, it was found that a post-treatment of calcined Co-Mo/β-Al₂O₃ greatly increase the HDS activity of the catalyst, accompanying the increase of the acidity.