Support effect over bimetallic ruthenium–promoter catalysts in hydrogenation reactions

The present work evaluates the influence of RuSn catalyst supported on La2O3, TiO2, SiO2 and Nb2O5 in dimethyl adipate (DMA) hydrogenation to obtain 1,6-hexanodiol. The catalysts were prepared by impregnation method, calcined and reduced at 673 K. The reactions were carried out in liquid phase in a Parr high pressure reactor at 528 K and 50 bar. The catalysts supported on SiO2 and Nb2O5 show higher selectivity to diol, 59% and 50% and conversion of 57% and 28%, respectively, indicating that the new active phases formed in the metal–support interface are able to hydrogenate the DMA ester group. The presence of positively charged tin species acting as Lewis acid sites could be considered as responsible for the carbonyl activation. It is also verified that a synergic effect between promoter and support is extremely important for the formation of 1,6-hexanediol.