New insides in the characterization of HDS industrial catalysts by HAADF-STEM

Hydrodesulfurization (HDS) catalysts are of great importance in the petroleum industry. Transition metal sulphides catalysts of Ni(Co)Mo(W)/Al$_{\mathrm{2}}$O$_{\mathrm{3}}$ are widely used for hydrotreating reactions, like hydrodenitrogenation and HDS. One of the main issue in these catalysts is to understand the mechanism of the reaction, where MoS$_{\mathrm{2}}$ plays the most important role in the catalytic activity. We studied an industrial NiMo/Alumina sulfide catalyst highly active by using aberration-corrected HAADF-STEM techniques. The used catalysts was a state-of- the art commercial nickel-molybdenum alumina-supported formulation, including organic agent modifier. This type of material belongs to a novel family of catalysts specially designed for ultra-low sulfur production from straight-run gas oil (SRGO), cycle oil, coker gas oil, or their combinations at operating conditions of commercial interest in hydrotreating units at industrial scale. Aberration corrected HAADF-STEM allowed to observe the nanostructure and location of MoS$_{\mathrm{2}}$ and his interaction with the alumina. The results indicate that the MoS$_{\mathrm{2}}$ is highly dispersed on the alumina, however the location of Ni is one of the task of this kind of catalyst.