Morphological and structural study of the Si deposition on the sulfided NiMo/γ-Al2O3 catalyst: Effect on the support

Morphological and structural study of the Si deposition on the sulfided NiMo/γ-Al2O3 catalyst: Effect on the support

Type	Journal Article
Author	P. Pérez-Romo
Author	J. Navarrete-Bolaños
URL	http://www.sciencedirect.com/science/article/pii/S0926860X14004682
Volume	485
Pages	84-90
Publication	Applied Catalysis A: General
Date	September 5, 2014
Abstract	In the hydroprocessing of coker naphtha, silica poisoning of hydrotreating catalysts poses a major challenge due to the deposition of Si species, which deactivate the catalyst and shorten its life time. Authors present deactivation results of the sulfided NiMo/γ-Al2O3 hydrotreating catalyst, obtained by running a long-term test. Researchers processed refinery coker naphtha in a continuous hydroprocessing unit in a mini-scale laboratory under industrial conditions. Catalyst samples were characterized. Si determination and the evolution of the structural characteristics of these samples were followed by 29Si MAS NMR, FTIR, textural analysis and scanning electron microscopy (SEM) performing microanalysis by dispersion energies (EDS). 29Si MAS NMR results confirmed the deposition and evolution of different Si species on the catalyst surface with the time on stream. The increasing content of Si species in the catalyst affected textural properties such as surface area and pore volume by decreasing them. As for the chemical properties, the Brønsted/Lewis (B/L) ratio was modified without increasing the coke formation and cracking activity.