Ir-Fe bimetallic catalysts for selective glycerol hydrogenolysis

Abstract

This work studied the effect of adding Fe to an Ir/γ-Al2O3 catalyst in different Fe/Ir molar ratios (0.5, 1.0, and 2.0) on the conversion and selectivity of the glycerol hydrogenolysis reaction. Additionally, the effect of the calcination of the solids was evaluated. The catalysts were prepared by incipient wetness impregnation of the Ir and Fe salts on the support and were characterized by textural analysis, XRD, TPR, XPS, and TEM-EDS techniques. The interaction between Ir and Fe was evidenced in the characterization of the catalysts. The addition of Fe to the Ir catalyst led to an increase in activity; however, this effect was better observed for the non-calcined catalyst series. The calcined catalyst series did not present a significant increase in glycerol conversion and selectivity to 1,2-PDO, probably due to the sintering of Ir occasioned by the catalyst's calcination, as observed in the characterization. For non-calcined bimetallic catalysts, the conversion increased from 7 % to 21.5 % for IrFe2.0/γ-Al2O3 catalyst, probably due to the synergic effect between both metals and the formation of Ir-Fe bimetallic particles, as evidenced in EDS mapping and XPS analysis. In the presence of this catalyst, selectivity to 1,2-PDO remained high (90.1 %).