Upgrading of lipids to renewable aviation fuels has attracted significant attention owing to the gradual depletion of fossil resources and environmental pollution problems. However, to design and develop the catalysts with excellent catalytic activity and stability is still a great challenge. Herein, hollow hierarchical silicalite-1 zeolite encapsulated Pt and PtNi bimetals (Pt@HS-1 and PtNi@HS-1) were successfully synthesized via a ship-in-bottle strategy and employed for hydroconversion of methyl stearate, as a model compound of lipids, to aviation fuel range alkanes in a continuous fixed-bed reactor. Their morphologies, texture, and acidity were characterized by FE-SEM, FE-TEM, XRD, N2-BET, H2-TPR, XPS, ICP-OES, NH3-TPD, and CO pulse chemisorption. The PtNi/S-1 and PtNi@HS-1 catalysts showed higher catalytic activity and selectivity to aviation fuel owing to the stronger cleavage ability related to the introduction of Ni species. Moreover, aviation fuel selectivity was significantly improved on the hollow hierarchical encapsulated catalysts than their precursors, ascribed to the extended contact time between reactants and active sites. A maximum aviation fuel selectivity of 45% was obtained for the PtNi@HS-1 catalyst at 360 °C under 3 MPa. Furthermore, the PtNi@HS-1 catalyst exhibited superior catalytic stability and selectivity than the PtNi/S-1 catalyst during the stability test. This indicates that the hollow hierarchical encapsulated structure plays crucial roles in enhancing aviation fuel selectivity and catalytic performance.

Selective hydroconversion of lipids to aviation fuel over hollow silicalite-1 zeolite encapsulated PtNi catalysts

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.