Abstract
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•CNTs as a cosupport with alumina is loaded with MoNi.•The catalyst showed significant improvement in HDS of DBT.•While alumina provides good mechanical properties, CNTs enhance the dispersion and acidity.•Direct desulfurization mechanism was proposed to be predominant.
Alumina-carbon nanotubes (AlCNTs) were prepared as a support and loaded with MoNi catalyst (AlCNTMoNi). The same catalyst without the carbon nanotubes (CNTs) was also prepared to investigate their role. Techniques including N2 physisorption analysis, temperature programmed analysis, X-ray diffraction and scanning electron microscopy were used for characterization. The BET surface areas of the AlMoNi and AlCNTMoNi were 165 and 214 m2/g, respectively, while the total acidity was 0.36 and 1.53 mmol/g, respectively. The catalysts were investigated for their performance in the hydrodesulfurization (HDS) of dibenzothiophene in fuels in a batch reactor. The fuel used consisted of decalin with 550 ppm S. DBT conversions of 99% and 87% were achieved using the AlCNTMoNi and AlMoNi catalysts, respectively. The AlCNTMoNi catalyst also showed better performance than the control samples without CNTs, and physically mixed AlMoNi and AlCNTMoNi were used for comparison. The results indicate that adding CNTs into the γ-Al2O3 support enhanced the catalytic activity towards HDS due to its textural properties and surface morphology. Interestingly, the AlCNTMoNi catalyst showed excellent stability for up to five cycles, which indicates its suitability for industrial applications.