The suppression of a basic nitrogen compound influence on hydrodesulfurization activity of dibenzothiophene in treated diesel over Al2O3 supported CoMo catalysts by ZrO2 as a secondary support

•The addition of ZrO2 enhances the HDS activity of CoMo/Al2O3 catalyst.•ZrO2 suppresses the influence of pyridine.•Pyrrole is friendly environment for CoMo/Al2O3 and CoMo/Al2O3–ZrO2 catalysts.

In this study, the effect of ZrO2 as a secondary support on HDS activity of dibenzothiophene in treated diesel over CoMo/Al2O3 catalysts has been investigated. The HDS activity of all prepared catalysts was evaluated at 350 °C and 8 MPa. It was found that CoMo/Al2O3–ZrO2 catalyst with 10 wt.% of ZrO2 exhibited the highest HDS activity. In the presence of pyridine, a basic nitrogen compound, the addition of ZrO2 obviously suppressed the influence of pyridine on the HDS activity of CoMo/Al2O3 based catalyst. These can be explained by the decrease of the total amount of acid sites on CoMo/Al2O3 catalyst when ZrO2 was added.

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