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 gamma-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 C-8 to C-15 with an iso- /n-paraffin ratio of ca. 6.8, perfectly meeting the standard specifications of bio-jet fuel.