Catalytic Hydrotreating Process Performance Over Noble Metal-Mesoporous Catalysts

In this work, the performance of a series of noble metal catalysts supported on the SBA-16 mesoporous matrix was studied. Its activity was measured in catalytic hydrotreating (HDT) reactions, such as tetralin hydrogenation in a batch reactor. The results were adjusted with a pseudo first order equation and then, the most active catalysts were tested in a continuous flow reactor under industrial-like conditions. Noble metal catalysts were synthesized, mainly monometallic iridium and bimetallic iridium-platinum and iridium-palladium supported SBA-16. The support was also modified with aluminum to provide Bronsted and Lewis acidity to the catalysts. All the catalysts were characterized by FTIR, XRD, NMR, N₂ isotherms, H₂ chemisorption, TPR and XPS to be able to relate the activity with the nature of the catalyst. The catalyst modified with 0.5 wt% of Ir, 0.5 wt% of Pt and 3 wt% of Al supported over SBA-16 matrix was the most active in tetralin hydrogenation to decalins in a Batch reactor, achieving the higher kinetic constant of 0.012 min⁻¹ and 90% of conversion to fully hydrogenated decalins at 120 min of reaction time. This catalyst also was the most active in the hydrogenation of tetralin using a continuous flow reactor obtaining the highest kinetic constant of all the catalysts tested with a value of 0.152 mol/h g cat. and achieving 90% of conversion to decalins at W/F = 150. Its greater activity was explained in terms of greater hydrogenating capacity, better dispersion of the active species, and greater resistance to deactivation thanks to the protective effect of the bimetallic alloy formed in synergy with a greater acidity of the aluminum-modified support. In this work, optimization has been achieved in the synthesis of an active, selective, contaminant-resistant catalyst with great stability. Very good results were obtained in a continuous process under conditions like to industrial ones.

Graphical Abstract