Cu-Based Catalysts for the One-Pot Condensation–Hydrogenation of Cyclopentanone to Produce Valuable SAF Precursors

Abstract

A process combining aldol condensation and hydrogenation of bio-based cyclopentanone (CPO) in a one-pot reaction is proposed. Cu-based bifunctional catalysts obtained from hydrotalcite-type precursors were found highly active in mild reaction conditions (i.e., 130–170 °C), producing valuable bicyclic (C10) and tricyclic (C15) aliphatic alcohols/ketones with interesting application as sustainable aviation fuel (SAF) precursors with enhanced properties. The presence of surficial strong basic sites active in aldol condensation, together with the formation of highly dispersed copper nanoparticles able to catalyze C═C and C═O hydrogenation (TOF of 0.06–0.16 s⁻¹), assured high catalytic efficiency and fine control of the products nature and distribution. From the optimization of both catalysts formulation and reaction conditions it was found that, properly tuning the Cu content, it is possible to drive products distribution towards the production of bicyclic (C10) aliphatic alcohol with high selectivity (75% at total CPO conversion, when Cu = 10 wt %, at 170 °C, 1.0 MPa of H₂) and short reaction time (4 h). The optimized catalyst formulation showed impressive stability over multiple reaction/regeneration cycles, demonstrating the high potential of the proposed catalytic process for future applications in sustainable biofuels production.