Ni–Fe Intermetallic Compound Catalysts for Lipid Deoxygenation to Produce Green Diesel: Crystallization Temperature Effect

Ni catalysts have recently been utilized in lipid deoxygenation to produce green diesel due to their economic and environmental benefits. However, the severe agglomeration of Ni sites and the small pore size of the Ni catalyst significantly restrain its catalytic performance. To address these issues, the Ni–Fe intermetallic compound (Ni–Fe–IM/Al₂O₃) catalyst was synthesized using Ni–Fe–Al layered double hydroxides (LDH) as the precursor, and the crystallization temperature of Ni–Fe–Al LDH was investigated. Ni–Fe–IM/Al₂O₃ from 50 °C achieved the highest catalytic performance due to its fine NiO particles, the largest surface area, and the lowest reduction temperature. In addition, the deoxygenation of gutter oil, acidified oil, soybean oil, and microalgae oil over Ni–Fe–IM/Al₂O₃-50 was also conducted and achieved more than 97.2% conversion and 92.5% alkane yield. In the continuous deoxygenation of acidified oil, Ni–Fe–IM/Al₂O₃-50 showed decent stabilization in 80 h of reaction. This study proposed a potential catalyst in the green diesel industry.