Promoter nature effect on the sensitivity of Ni–Mo/Al2O3, Co–Mo/Al2O3, and Ni–Co–Mo/Al2O3 catalysts to dodecanoic acid in the co-hydrotreating of dibenzothiophene and naphthalene

Abstract

The promoter nature effect on the sensitivity of Mo/Al₂O₃, Ni–Mo/Al₂O₃, Co–Mo/Al₂O₃, and Ni‒Co–Mo/Al₂O₃ catalysts to dodecanoic acid in the hydrotreating of a mixture containing dibenzothiophene and naphthalene has been investigated. The experiments have been carried out using a flow-through setup. The catalysts have been prepared using the PMo₁₂ heteropoly acid, Сo(Ni) citrates, and Co₂Mo₁₀ heteropoly acid and have been characterized by high-resolution transmission electron microscopy. The highest hydrodesulfurization activity in the presence of dodecanoic acid is shown by the trimetallic catalyst Ni–Co–Mo/Al₂O₃. The introduction of Ni is favorable for dodecanoic acid conversion via the hydrogenation route, thus increasing the С₁₁: С₁₂ ratio in the conversion products. Effective dodecanoic acid adsorption constants under the hydrotreating conditions have been calculated using the Langmuir–Hinshelwood model.