Structure Engineering of Ni/SiO₂ Vegetable Oil Hydrogenation Catalyst via CeO₂

Inspired by our finding that metallic Ni particles could be uniformly distributed on a reduced CeO₂ surface and stabilized on Ce³⁺ sites, we suppose a possible improvement in the activity and selectivity of the MgNi/SiO₂ vegetable oil hydrogenation catalyst by increasing the surface metal Ni availability via modification by ceria. The proposed approach involved the addition of a CeO₂ modifier to the SiO₂ carrier and as a catalyst component. Evaluation of the structure, reducibility, and surface and electronic states of the CeO₂-doped MgNi/SiO₂ catalyst was performed by means of the Powder X-ray diffraction (PXRD), Scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), and X-ray photoelectron spectroscopy (XPS) combined with High-resolution transmission electron microscopy (HRTEM), Temperature-programmed reduction with hydrogen (H2-TPR), and H₂-chemisortion techniques. So far, no studies related to this approach of designing Ni/SiO₂ catalysts for the partial hydrogenation of vegetable oil have been reported. The added ceria impact was elucidated by comparing fatty acid compositions obtained by the catalysts at an iodine value of 80. In summary, tuning the hydrogenation performance of Ni-based catalysts can be achieved by structural reconstruction using 1 wt.% CeO₂. The introduction mode changed the selectivity towards C18:1-cis and C18:0 fatty acids by applying ceria as a carrier modifier, while hydrogenation activity was improved upon ceria operation as the catalyst dopant.