Superior Long-Term Stability of a Mesoporous Alumina-Supported Pt Catalyst in the Hydrodeoxygenation of Palm Oil

Abstract

Catalyst stability in the hydrodeoxygenation of vegetable oils is one of the big challenges for practical production of bio-jet fuel. Particularly, supported Pt catalysts are known to show activity decay because of Pt sintering and coking. Herein, we report superior long-term stability of the Pt catalyst in the hydrodeoxygenation of palm oil by using the mesoporous I-Al2O3 (MA) support synthesized by solvent-deficient precipitation (SDP). When the MA was prepared with a molar ratio of water to aluminum isopropoxide being five, the space-time yield of the Pt catalyst was maintained at ca. 6.09 mol kg-1 h-1 for over 80 h, which was much better than those of the other Pt catalysts. This result was attributed to the two properties such as well-developed mesopores of a larger diameter than 20 nm in the fresh MA and strong metal-support interaction of Pt/MA. Therefore, the SDP method could endow the alumina support with textural and chemical benefits for stable performance. Furthermore, the hydrodeoxygenated palm oil was converted into paraffinic hydrocarbons mainly ranging from C8 to C15 with an iso-/n-paraffin ratio of ca. 6.8, perfectly meeting the standard specifications of bio-jet fuel.