Ethanol Upgrading to Jet Fuel Precursors over Ni/MgO@C Catalysts Derived from Bimetallic Metal–Organic Frameworks

The growing demand for sustainable aviation fuel (SAF) makes extending the carbon chain from ethanol a strategy well worth pursuing. Herein, a series of Ni/MgO@C catalysts derived from Ni/Mg bimetallic metal–organic frameworks (MOFs) was evaluated for the Guerbet coupling of ethanol to higher alcohols within the alcohol-to-jet (ATJ) strategy. Owing to the isolated metal nodes in the periodic framework, highly dispersed Ni species on the magnesium-based solid supports with abundant basic sites have been accessed. The catalyst with a Ni/Mg molar ratio of 0.13 achieved a higher alcohol yield of 55.5% at 88.4% ethanol conversion under 2 MPa N2 at 240 °C for 10 h. Upon extending the reaction to 24 h, C8–C16+ alcohols accounted for 41.4% of the alcohol product pool. Comprehensive catalyst characterization combined with theoretical calculations revealed that the involvement of Ni species can accelerate the dehydrogenation step, while an appropriate Niδ+/Ni0 ratio can be critical for efficient carbon chain elongation by promoting alcohol dehydrogenation to aldehyde and simultaneously suppressing their deep decomposition through weakened interaction with the catalyst surface.