The Growth and Reactivity of Palladium Oxide Thin Films

Palladium is often used to catalyze the oxidation of fuel in internal combustion engines, helping to minimize the amount of CO, NOx, and volatile organic carbons produced. Under normal operating conditions, Pd goes through a variety of complex oxidation stages. In this research, palladium oxide was studied. By growing PdO thin films using epitaxial growth methods, specific surfaces of the metal oxide can be examined. Analyzing a variety of surfaces and their catalytic behavior will lead to a better fundamental understanding of the catalytic properties of PdO. However, because of the thermodynamic instability of PdO, challenges arise in trying to grow these thin films. In this research, the growth and reactivity of the PdO (110) surface on Co3O4 (110)/ MgAl2O4 (110) substrates was examined. While PdO (110) does grow on these substrates, the extent of growth of ordered crystals relies heavily upon the physical quality of the substrates. Temperature programmed desorption (TPD) experiments show that PdO (110) on Co3O4 (110)/ MgAl2O4 (110) does oxidize CO to CO2 to a small extent at around 430 K.