What question did this study set out to answer?

The aim is to evaluate how zirconia incorporation and different template materials affect NiMo/Al2O3-ZrO2 catalyst properties and performance in hydrodesulfurization and hydrogenation reactions.

April 15, 2026Open Access

Role of ZrO2 and Porosity Induced by Activated Carbon and Starch Templates in NiMo/Al2O3-ZrO2 Catalysts for Naphthalene Hydrogenation and 4,6-Dimethyldibenzothiophene Hydrodesulfurization

Key Points

The aim is to evaluate how zirconia incorporation and different template materials affect NiMo/Al2O3-ZrO2 catalyst properties and performance in hydrodesulfurization and hydrogenation reactions.
Catalysts prepared via co-impregnation on supports using a sol-gel method with starch and activated carbon as templates.
Characterization methods included SEM-EDX, N2 physisorption, H2-TPR, XPS, HRTEM, and pyridine-FTIR.
Measured physicochemical properties include surface area, reducibility, metal distribution, acidity, and reaction rates.
NiMo/Al2O3-ZrO2(C) achieved a hydrodesulfurization conversion of 40% with a TOF of 4.69 × 10−5 s−1.
NiMo/Al2O3-ZrO2(A) resulted in 97.18% naphthalene conversion with a TOF of 12.9 × 10−3 s−1.
Zr incorporation led to a significant increase in sulfidation index from 47.1% to 73.9% and enhanced reducibility.

Abstract

The influence of zirconia incorporation and template type on the physicochemical properties of NiMo/Al2O3-ZrO2 catalysts was investigated for the hydrodesulfurization (HDS) of 4,6-dimethyldibenzothiophene (4,6-DMDBT) and the hydrogenation (HYD) of naphthalene (N). Catalysts were prepared by co-impregnation on supports synthesized via a sol-gel method using starch (A) and activated carbon (C) as structure-directing templates, followed by zirconium incorporation through a grafting procedure. The resulting materials were characterized by SEM–EDX, N2 physisorption, H2-TPR, XPS, HRTEM, and pyridine-FTIR. SEM-EDX confirmed homogeneous metal distributions and compositions close to nominal values (Mo = 20 wt%, Ni = 5 wt%, Zr = 11 wt%) with Ni/(Ni + Mo) = 0.30. N2 adsorption–desorption isotherms correspond to type IV(a) with H3-H4 hysteresis loops, characteristic of mesoporous structures. After metal incorporation, surface areas decreased to 96 m2 g−1 for NiMo/Al2O3 and 81 m2 g−1 for Zr-modified catalysts, while the activated carbon-templated sample preserved a larger mesoporous volume (0.335 cm3 g−1) and higher macroporosity (72%). H2-TPR profiles indicated improved reducibility for Zr-containing catalysts. XPS revealed an increase of MoS2 species from 45% in NiMo/Al2O3 to 75% in NiMo/Al2O3-ZrO2(C), accompanied by a higher degree of sulfidation index (DSI) from 47.1% to 73.9%. HRTEM analysis of Zr-modified catalysts revealed longer MoS2 slabs (11.8–12.1 nm) and higher edge-to-corner ratios (17–17.4) compared with NiMo/Al2O3 (6.2 nm; fe/fc = 8.2). Pyridine-FTIR showed a substantial increase in total acidity from 91 to 421 μmol g−1 upon Zr addition. Catalytically, NiMo/Al2O3-ZrO2(C) exhibited the highest HDS conversion (40%), reaction rate (10.5 × 10−9 mol s−1 g−1), and TOF (4.69 × 10−5 s−1), whereas NiMo/Al2O3-ZrO2(A) reached the highest naphthalene conversion (97.18%), with a reaction rate of 27.4 × 10−7 mol s−1 g−1 and TOF of 12.9 × 10−3 s−1. These results demonstrate that Zr incorporation and the activated carbon template favored hydrodesulfurization, whereas the starch template promoted hydrogenation performance.

Role of ZrO2 and Porosity Induced by Activated Carbon and Starch Templates in NiMo/Al2O3-ZrO2 Catalysts for Naphthalene Hydrogenation and 4,6-Dimethyldibenzothiophene Hydrodesulfurization

Key Points

Abstract

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