Exploring metal and non metal promoters for Pd single atoms on CeO2 for CO oxidation

The catalytic oxidation of carbon monoxide (CO) remains a cornerstone reaction in environmental catalysis, with cerium oxide (ceria) being a widely studied catalyst due to its remarkable redox properties. This thesis explores the effect of metal (zirconium) and non-metal (boron) promoters on the structural and catalytic behavior of ceria-based materials for CO oxidation. The catalysts were synthesized using flame spray pyrolysis (FSP), a scalable and versatile technique that ensures high dispersion and size control or the active phases. Both zirconium and boron were found to significantly enhance the thermal stability of ceria. Raman spectroscopy revealed that zirconium doping increased the concentration of oxygen vacancies, a key factor in improving redox behavior and activity towards CO oxidation. The kinetic behavior of the catalysts was probed through activity measurements and determination of reaction orders. Interestingly, the presence of promoters led to distinct mechanistic modifications. In zirconium-doped ceria, CO exhibited a poisoning effect, as indicated by a negative reaction order. In contrast, boron-doped ceria displayed a positive reaction order for CO, suggesting a promotional role in the oxidation process. The study highlights the potential of dopant engineering to fine-tune catalyst behavior and opens pathways for the design of optimized materials for low-temperature oxidation reactions.