Acid-base properties and the hydrofining activity of NiMo catalysts incorporated on alumina modified with F− and Cl− Original Research Article

A series of studies on NiMo catalysts incorporated on to Al2O3 modified with chloride and fluoride ions was carried out. As the test reactions, the reactions of decomposition of 2-propanol and diacetone alcohol as well as of ethylbenzene were employed. The obtained catalysts were also tested in hydrofining of coal liquid. It was observed that modification of the support with fluoride and chloride ions in the studied range of concentrations increases the acidity of the catalyst. A distinctly higher increase in acidity was obtained for the modification with F− ions than with Cl− ions. The applied modifiers, on the one hand, lead to the increase in the activity of the catalysts in the reactions of decomposition of 2-propanol to propene, ethylbenzene to styrene, but on the other hand, reduce their activity in the decomposition of diacetone alcohol to acetone. Modification with Cl− and F− ions only insignificantly affects the activity of catalysts in hydrodesulfurization (HDS) of coal liquid. Introduction of fluoride ions on the support of NiMo catalyst leads to a quite large increase of the activity in hydrodenitrogenation (HDN) of coal liquid, whereas, when modified with chloride ions, these catalysts bring about a decrease in the activity of the discussed reaction. The properties of catalysts generated by ions of the modifiers, in particular the type and strength of acid centers, play a significant role in the HDN of coal liquid.