Abstract:Fatty alcohols are important chemical raw materials in modern industry and are widely used in cosmetics, household chemicals, pesticides, and fine chemicals. They are considered highly valuable in industry. They are primarily derived from animal and vegetable oils or their derivatives and are produced via high-pressure hydrogenation reactions. However, Cu-Cr-based catalysts commonly used in industry face the problem of Cr loss during use, leading to catalyst deactivation and environmental issues. Therefore, the current research focus has shifted to the design and preparation of highly selective, heterogeneous, chromium-free ester hydrogenation catalysts. This study utilized green rust, a layered hydroxide with a hydrotalcite-like structure (Fe2+, Fe3+, and ), produced during α-FeOOH synthesis. Cu species were then loaded onto α-FeOOH via deposition by precipitation, yielding a highly active, calcination-free catalyst for oil ester hydrogenation. The surface structure and physicochemical properties of the catalyst were characterized by XRD, XPS, and TEM to explore the synergistic effects of Cu and Fe species in the catalytic hydrogenation of methyl palmitate to hexadecanol. The results showed that under in-situ reduction conditions, Fe species were converted from α-FeOOH to Fe3O4, and Cu species from Cu2(OH)2CO3 to Cu0, respectively. Following optimization, the 10Cu-G catalyst achieved>99% methyl palmitate conversion and near-100% hexadecanol selectivity under the following conditions: 300 ℃, 10 MPa H2, 2 h. Combining the characterization results, activity test results, and the temperature and pressure changes in the reactor during the reaction, the following reaction mechanism was proposed: the highly dispersed Cu0 species on the catalyst surface and the abundant Lewis acid sites on the Fe3O4 surface synergistically participate in the activation and dissociation of H2 and the activation and conversion reaction of methyl palmitate; H2 dissociates into active H· on Cu0, and the C=O bond of methyl palmitate is adsorbed and activated on the Lewis acid sites on the Fe3O4 surface; the generated H· attack the activated C=O bonds and promote the dissociation of methyl palmitate to generate hexadecanol; the Lewis acid sites occupied by O atoms react with H2 to achieve the regeneration of Lewis acid sites. This study provides valuable insights for the design and development of Cr-free ester hydrogenation catalysts. Close-