One-step propylene formation from bio-glycerol over molybdena-based catalysts

Abstract

This work presents a novel, one-step catalytic process, enabling highly selective propylene formation via glycerol hydro-deoxygenation (HDO) reactions. Fe–Mo catalysts, supported on black and activated carbons, are selective towards C–O bond cleavage, thus converting glycerol to propylene with high yields. BET, XRD, TPD-NH₃ and TPD-He methods have been employed for the characterization of the samples. Molybdenum oxide, at its reduced state, is essential for driving selectively the reaction towards complete deoxygenation. The only product of glycerol HDO is propene, in the gas phase, while 2-propenol, propanols and propylene glycol have been detected, among others, in the liquid phase. Under the standard reaction conditions (300 °C temperature, 8.0 MPa hydrogen pressure), glycerol conversion exceeds 88% and selectivity to propene reaches 76% after 6 hours of reaction. This study includes the investigation of the operating conditions effect (i.e. reaction time, reaction temperature, catalyst loading and H₂ pressure) regarding glycerol HDO towards propene formation.