Advantage of Ni/SBA-15 catalyst over Ni/MgO catalyst in terms of catalyst stability due to release of water during nitrobenzene hydrogenation to aniline

Two catalysts, Ni/SBA-15 and Ni/MgO were prepared by wet impregnation technique with 5 wt.% Ni loading in each catalyst. These were tested for nitrobenzene hydrogenation to aniline reaction under vapor phase at atmospheric pressure. Ni/MgO suffered a huge loss in the activity (conversion) during time on stream study even though the Ni dispersion is larger compared to that in SBA-15 supported catalyst. TPR studies of used catalysts confirm coking of the catalysts. The superior catalytic activity in terms of conversion and selectivity during time on stream operation exhibited by Ni/SBA-15 catalyst is due to the hydrophobic nature of this catalyst (resistant to water generated during the reaction) and the effect of coking is not significant.

Graphical abstractHydrophobic nature of SBA-15 makes Ni/SBA-15 an ideal catalyst for nitrobenzene hydrogenation to aniline.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► The hydrophobic nature of SBA-15 makes Ni/SBA-15 a robust catalyst. ► Deactivation of Ni/MgO is due to adsorption of water generated during the reaction. ► The role of carbon deposition during the reaction is insignificant on the activity. ► Strong interaction between Ni and MgO favors higher Ni dispersion.