Study on the Hydrogenation of Ethyl Stearate to the Fatty Alcohol 1-Octadecanol over Ru on Tungstated Zirconia

Abstract

Fatty alcohols are important products in the chemical industry, given that they are frequently used in the formulation of surfactants and lubricants. In this context, this work describes a catalytic heterogeneous approach for the production of 1-octadecanol (C18OH) from ethyl stearate (ES) using nanosized Ru-supported on tungstated zirconia (W/Zr). The activity and selectivity of this series of catalysts have been studied during the hydrogenation of ES in a batch reactor at 175 °C and PH2 = 40 bar. The so-prepared catalysts were characterized by a sort of characterization techniques (i.e., X-ray diffraction, H2-TPR, etc.), confirming the high dispersion and higher reducibility of Ru nanoparticles on the W/Zr surface (primarily tetragonal zirconia) with respect to pure zirconia. Overall, the catalysts were significantly active. In addition, a strong synergistic effect was revealed between Ru and W species, according to catalytic data. Finally, the reaction sequence towards fatty alcohol has also been elucidated, pointing to the ester hydrogenolysis to the aldehyde and ulterior hydrogenation of the latter as the main route for fatty alcohol formation.