Enhanced Hydrodeoxygenation Selectivity of Fatty Acid over FeReOx/CeO2 Catalyst to Produce Fatty Alcohols and Alkanes

The selective hydrogenation of natural oils to produce fatty alcohols is a key process for synthesizing liquid alkanes and high-value chemicals. However, the development of catalysts capable of enhancing hydrodeoxygenation (HDO) selectivity while suppressing carbon–carbon (C–C) bond cleavage to minimize carbon loss remains a significant challenge. In this study, a FeReOx/CeO2 catalyst was developed, which was characterized by high selectivity to octadecanol (93.8%, 210 °C) and liquid alkanes from stearic acid under mild conditions. Notably, the FeReOx/CeO2 catalyst exhibited a higher hydrodeoxygenation selectivity in the production of liquid alkanes than decarboxylation (DCO) (C18: 84.2% vs C17: 15.8% at 240 °C). Detailed characterization of the FeReOx/CeO2 catalyst revealed that excellent catalytic activity originated from the synergistic interaction between Fe and ReOx. The introduction of ReOx not only enhanced the adsorption of stearic acid but also improved the dispersion of metallic Fe. The weak acidity of metallic Fe could inhibit the cleavage of the C–C bond to a certain extent to obtain alkane products with high hydrodeoxygenation selectivity. Furthermore, the catalyst exhibited strong stability without significant deactivation after five cycles.