Highly selective hydrogenation of stearic acid to fatty alcohols and alkanes over non-noble MFe/Fe3O4 catalysts

CuFe/Fe 3 O 4 enables selective HDO of stearic acid to C 18 alcohols and alkanes under mild conditions. • Oxygen vacancies and Lewis acid sites promote C O activation and suppress C C cleavage. • CuFe/Fe 3 O 4 shows excellent reusability over 23 consecutive catalytic runs. The development of highly efficient and tunable non-noble metal catalysts for the hydrogenation conversion of stearic acid offers a vital pathway for the sustainable production of fatty alcohols and alkanes. This study designed and synthesized a series of MFe/Fe 3 O 4 (M = Cu, Co, Ni) bimetallic catalysts, systematically investigating their catalytic performance differences and structure–performance relationships in the hydrodeoxygenation (HDO) of stearic acid. The CuFe/Fe 3 O 4 catalyst exhibited excellent activity and high selectivity, achieving complete conversion of stearic acid with an C 18 alcohol yield of 96.5% under conditions of 220 °C, 4 MPa H 2 , and 3 h. By adjusting the reaction temperature, selective control over the product distribution between C 18 alcohol and C 18 alkane was realized, with an C 18 alkane yield of 97.1% achieved at 280 °C, highlighting excellent pathway selectivity and carbon atom utilization. Experimental and characterization results suggest that the introduction of a second metal facilitates hydrogen dissociation, while surface oxygen vacancies enhance the adsorption and activation of the C O group. Moreover, moderate Lewis acid sites contribute to the gentle polarization of the carbonyl group and simultaneously suppress C C bond cleavage, thereby synergistically improving selectivity toward the hydrodeoxygenation (HDO) pathway. The catalyst also exhibits excellent substrate compatibility and reusability, maintaining high catalytic activity after 23 cycles. The combined regulation of the HDO pathway by these three factors enables the efficient and selective synthesis of either C 18 alcohol or C 18 alkane, providing a theoretical foundation for the structural optimization of high-performance non-noble metal hydrogenation catalysts and the elucidation of their reaction mechanisms.