Co-Mo Catalysts Supported on CNT/H-ZSM-5 Composites for Selective Production of Sustainable Aviation Fuel-Range Alkanes

Abstract

The aviation industry faces increasing pressure to reduce greenhouse gas emissions, driving interest in the development of sustainable aviation fuel (SAF) derived from lipid-based feedstocks. However, some challenges remain, particularly the need for complete deoxygenation of triglycerides, followed by efficient cracking and isomerization to yield hydrocarbons within the C8-C16 SAF range. One promising approach involves designing catalysts with complementary chemical and structural properties tailored for these transformations. In this work, an innovative catalytic support was developed by combining carbon nanotubes (CNTs) and an H-ZSM-5 zeolite through a solvent-free ball-milling process, aiming to create composites with optimized textural and chemical characteristics for SAF production from a lipid model compound, palmitic acid. The synthesis parameters (milling time and frequency) were systematically investigated to tune the structures of the resulting composites. These supports were subsequently impregnated with Co-Mo to produce bifunctional bimetallic catalysts. Catalytic performance tests identified the composite milled for 60 min at 10 vibrations s-1 as the most effective. Comparisons with physical mixtures and single-component catalysts highlighted the role of CNT-zeolite interaction in enhancing product selectivity. Furthermore, increasing the amount of CNT relative to H-ZSM-5 to a 2:1 weight ratio shifted selectivity toward SAF fractions, achieving 21.2% C8-C16 iso-alkanes, 12.4% linear alkanes, and 5.5% aromatics. These findings demonstrate the potential of this approach for engineering advanced bifunctional catalysts for sustainable aviation fuel production from lipid feedstocks.