Understanding the Chemical and Electronic Properties of Sub‐Monolayer TiO₂ on High Surface Area Silica for Jet Fuel Synthesis Applications

Abstract 2.5% of global carbon emissions result from air travel, underscoring the need for sustainable aviation fuels (SAF) derived from second‐generation lignocellulosic biomass to enhance the green credentials of the aviation sector. This study demonstrates the first solvent‐free photocatalytic conversion of furfural (FAL) and cyclopentanone (CPO) to produce 2,5‐bis(2‐furylmethylidene)cyclopentanone (F 2 Cp), a jet fuel precursor, using Ti‐SBA‐15 catalysts, synthesized via alkoxide grafting and controlled titanium surface coverage. Sub‐monolayer titania films on SBA‐15 supports are achieved with tuneable Ti content, confirmed by XPS (X‐ray photoelectron spectroscopy), UPS (ultraviolet photoelectron spectroscopy), REELS (reflectance electron energy loss spectroscopy), ISS (ion scattering spectroscopy), and Raman analysis. XPS analyses reveal coverage‐dependent Ti speciation, transitioning from isolated Ti atoms to interconnected Ti‐O‐Ti networks, with corresponding shifts in Auger parameters, indicating increased surface polarizability and Lewis acidity. Optimized Ti‐SBA‐15 catalysts exhibit a fourfold activity enhancement in photocatalytic activity over bulk TiO₂, attributed to improved mass transport, active site accessibility, and surface stability. This work highlights the potential of rationally designed hierarchical catalysts for scalable, energy‐efficient biomass valorization into SAF precursors, offering a scalable, energy‐efficient pathway for sustainable jet fuel production. By elucidating the structure‐function relationships in sub‐monolayer Ti‐SBA‐15 materials, this study provides critical insights for advancing photocatalytic technologies in renewable energy applications.