Selective Hydroconversion of Polyaromatics into High-Density Endothermic Aviation Fuel over Highly Dispersed Pt/FAU Catalyst

Abstract

Selective hydroconversion of polyaromatics enriched in biomass pyrolysis oil into alkyladamantanes (PSA) and multibranched polycycloalkanes (SRO) for high-density endothermic aviation fuels (HEAFs) is a pivotal technological approach to satisfying the growing energy demand of the aerospace sector and mitigating the enormous pressure of environmental pollution. Herein, zeolites with MFI, FER, *BEA, and FAU topologies supported Pt catalysts, fabricated via an enhanced strong electrostatic adsorption strategy, were used to investigate the conversion route of phenanthrene in a fixed-bed reactor, and the products were identified using a comprehensive GC×GC-MS/FID device. Highly dispersed Pt clusters on the as-synthesized bifunctional catalysts were confirmed by XRD and HRTEM techniques. Compared to Pt/FER catalyst, Pt/MFI exhibited an ascendant deep hydrosaturation ability with perhydrophenanthrene as the main product at 180–280 °C. In contrast, significantly higher amounts of PSA and SRO were yielded on Pt/BEA and Pt/FAU owing to the favorable match between the dimensions of these species and the porous channels. The conversion pathway was established as follows: phenanthrene preferentially undergoes hydrosaturation, followed by skeletal rearrangement and cycloisomerization to generate PSA and SRO, ultimately resulting in the formation of cracking products. Monte Carlo simulations further verified that PSA and SRO primarily form within the pores and supercages of acid zeolites. Notably, Pt/FAU catalyst exhibited a significantly high HEAFs yield of 42.6 wt %. The prepared HEAFs demonstrated a density of 0.957 g/mL, net heat of combustion of 40.3 MJ/L, and ignition delay time of 2935 ms. These properties surpass those of JP-10, underscoring their exceptional potential in advanced aerospace applications.

Topics & Concepts