Effect of Method of Boron Introduction into NiMo/Al2O3 Protective-Layer Catalysts on the Removal of Silicon from Diesel Fractions

NiMo/γ-Al2O3 protective-layer catalysts for removing silicon from diesel fractions were examined. The catalysts differ in the way in which boron is introduced into the support. The supports and catalysts were examined by X-ray diffraction analysis, transmission electron microscopy, IR spectroscopy, and adsorption–desorption of nitrogen. The catalysts were tested in hydropurification of the diesel fraction to which decamethylcyclopentanesiloxane was added as a model silicon compound. It was shown that introduction of boron into the support results in that the surface area of the supports and catalysts increases. If boron is introduced into pseudoboehmite, massive particles of the Ni–Mo–S phase are formed. It was found that the highest capacity for silicon is observed for the catalyst into which boron is introduced in the stage of pseudoboehmite preparation.