A comparative study of the performance of Pt/MgF2, Ir/MgF2 and Ru/MgF2 catalysts in hydrogenation reactions

Abstract This paper reports results of a comparative study of the structure and activity of MgF 2 -supported metal (Me) catalysts containing 1 wt.% of platinum, iridium or ruthenium. Their activities for hydrogenation of toluene and selective hydrogenation of ortho-chloronitrobenzene to ortho-chloroaniline were compared with the hydrogenation performance of metal catalysts prepared by impregnation of a alumina which is one of the most widely used supports. The catalysts were characterized by using low-temperature nitrogen adsorption, TPR-H 2 and H 2 -chemisorption techniques. The nature of metal and support appeared to have a clear influence on metallic phase dispersion and it was reflected by the activity of Me/MgF 2 catalysts. The application of magnesium fluoride as a support has enabled to obtain catalysts showing high activities for hydrogenation of toluene at 323–498 K and selective hydrogenation of ortho-chloronitrobenzene (o-CNB) to ortho-chloroaniline (o-CAN) in the liquid-phase at 353 K under hydrogen pressure of 4 MPa. From among the catalysts studied, the highest activity for the both aforementioned reactions has been found in the case of MgF 2 -supported platinum catalyst and the highest selectivity (100%) in that of ruthenium-containing catalyst. The activity of magnesium fluoride-supported catalysts was several times higher than that of alumina-supported ones.