Preparation of Palladium Nanoflowers Supported on Carbon Catalyst and Its Effect on the Electrochemical Hydrogenation of Soybean Oil

The efficiency of oil hydrogenation processes is significantly influenced by the morphology of the catalyst. This study aims to enhance the catalytic efficiency and longevity of palladium nanoflower (PdNFs) catalysts by developing catalysts with a high specific surface area and abundant active sites. Using an electrochemical hydrogenation system, the effects of this catalyst on trans fatty acid (TFA) content and hydrogenation selectivity in the hydrogenated oil were investigated. A controlled-morphology palladium nanoflowers supported on carbon (PdNFs/C) catalyst was synthesized via a chemical reduction process and subsequently used to electrochemically hydrogenate soybean oil. Results indicated that heating duration substantially impacts the morphology of palladium catalysts. Specifically, insufficient or excessive heating times reduce the specific surface area and crystallization degree of palladium nanoparticles (PdNPs), thereby affecting catalytic performance. The electrochemically active surface area (ECSA) of PdNFs/C, prepared with a heating time of 35 min, reached 230.75 cm² mg^-1, whereas the ECSA of Pt/C under the same conditions was only 225.41 cm² mg^-1. In addition, the ECSA loss rate of PdNFs/C was only 50% of that observed in commercial Pt/C. After three hours of hydrogenation, the iodine value of soybean oil treated with PdNFs/C catalyst decreased to 86.58 g I₂/100 g, and the TFA content increased from 1.05% in the original soybean oil to 1.15%, which is an increase of only 0.1%, while maintaining higher linoleic acid selectivity. These findings suggest that PdNFs/C has strong potential as a highly efficient catalyst for soybean oil hydrogenation applications. PRACTICAL APPLICATION: This study explores the development of safe and health-conscious catalysts for producing low trans fatty acid (TFA) hydrogenated plant oils, aiming to preserve product taste while reducing the risk of coronary heart disease, hypertension, and other related health concerns, thereby enhancing food safety. The findings provide valuable insights into the preparation of low TFA hydrogenated soybean oil through electrochemical hydrogenation technology. This research offers theoretical support for developing new catalysts and advancing electrochemical hydrogenation processes in the oil hydrogenation industry.