Engineering of Ce3+-O-Ni structures enriched with oxygen vacancies via Zr doping for effective generation of hydrogen from ammonia

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.

Recent Progress on Hydrogen Production from Ammonia Decomposition: Technical Roadmap and Catalytic Mechanism

Ammonia decomposition has attracted significant attention in recent years due to its ability to produce hydrogen without emitting carbon dioxide and the ease of ammonia storage. This paper reviews the recent developments in ammonia decomposition technologies for hydrogen production, focusing on the latest advances in catalytic materials and catalyst design, as well as the research progress in the catalytic reaction mechanism. Additionally, the paper discusses the advantages and disadvantages of each method and the importance of finding non-precious metals to reduce costs and improve efficiency. Overall, this paper provides a valuable reference for further research on ammonia decomposition for hydrogen production.