Resumo

VILLARREAL, A.; GUTIERREZ-ALEJANDRE, A.  e  RAMIREZ, J.. Catalizadores de hidrodesulfuración NiMo/SiO₂/Al₂O₃. Estudio por FTIR de la interacción ácido cítrico-soporte. Superf. vacío [online]. 2016, vol.29, n.1, pp.14-18.  Epub 23-Out-2020. ISSN 1665-3521.

The interaction of citric acid with alumina grafted with silica was studied by infrared spectroscopy. The results indicate that citric acid coordinates to the Al3+ Lewis centers and interacts by hydrogen bonding with the type II and III hydroxyl groups in the alumina support, which after the addition of 15 wt% citric acid to the alumina support are almost completely eliminated, decreasing the acidity and the possibility of strong metal-support interactions between the alumina support and the Mo phases in the final HDS catalyst. The effect of citric acid is greater in the catalyst prepared by post-treatment in which the decrease in acidity results in catalysts with smaller MoS2 crystallites and higher number of active sites, resulting in an increase of 22 % in the HDS of 4,6-dimethyldibenzothiophene.

Palavras-chave : Hydrodesulfurization; NiMo/SiO₂/Al₂O₃ catalysts; citric acid; FTIR.