Dual-site Re/In2O3 enables selective hydrodeoxygenation of fatty acids via suppressed decarbonylation

Selective deoxygenation of fatty acids to diesel-range alkanes without carbon-chain shortening is essential for sustainable biomass upgrading, but high selectivity remains challenging by competing decarbonylation/decarboxylation pathways. Here, a Re/In 2 O 3 featuring Re single atoms and ReO 3 clusters was synthesized for the hydrodeoxygenation of stearic acid. In contrast to In 2 O 3 , which primarily yields 1-octadecanol (93.1% selectivity) with minimal n-octadecane (1.2% selectivity), the optimized Re/In 2 O 3 catalyst achieves 100% selectivity diesel-range alkanes (>85% n-octadecane). Isotopic labeling, in situ spectroscopy, and kinetic analyses reveal Re-induced synergy: ReO 3 enhance H 2 dissociation, while Re single atoms promote bidentate adsorption of fatty acids, and oxygen vacancies in In 2 O 3 facilitate selective C–O bond cleavage. This multifunctional synergy suppresses C–C bond scission and significantly lowers the apparent activation energy for hydrodeoxygenation by 36.5 kJ·mol −1 . The catalyst exhibits broad applicability across diverse carboxylic acids, including unsaturated and aromatic substrates, underscoring its potential for efficient biomass utilization.