Oxygen reduction reaction (ORR) is one of the most studied reactions for clean energy devices such as fuel cells and metal-air batteries due to its intrinsically sluggish kinetics which often limits device performance. Non-precious transmission metal oxides (TMO) such as Fe3O4, MnOx and Co3O4[1] have been intensively probed as alternatives to platinum-based catalysts. To supplement low electronic conductivity of TMOs, they are often dispersed on a highly conductive carbon nanostructure with a large surface area, maximizing catalytically active sites per volume and mass. We employ a hybrid structure where both cobalt and cerium nitrate salts with a ligand called [1,1’-Biphenyl]-4,4’-dicarboxylic acid create an MOF (MOF-Ce-Co) with extreme surface area and excellent electronic conductivity using the hydrothermal process and pyrolysis. While this structure is conductive, its conductivity can be improved with the functionalization of cerium particles. Specifically, Ce(IV) complexes have been reported to show superior rates of phosphonate ester bond cleavage compared to other metal oxides. The unprecedented activity of Ce(IV) has been attributed to the role of the Ce(IV) 4f orbitals that can mix with the orbitals of the P=O bond to form hybrid orbitals[2]. To functionalize cerium, phosphoric acid is used to bind a phosphate group onto cerium oxide. This gives rise to a penta-coordinate intermediate that is susceptible to a nucleophilic attack[2]. The treated MOF-Ce-Co is then hydrothermally reacted (at 160 ºC for 24 h) with the precursor P25, thus creating MOF-Ce-Co with TiO2 attached. Results have indicated that phosphate groups not only absorb cerium nanoparticles, but TiO2 thus resulting in enhance performance in terms of current density, and onset/half-wave potential as seen in both CV and LSV data. FT-IR results indicate that an absorption of 1040 cm-1 (corresponding to a phosphate group) appeared once MOF-Ce-Co was treated with phosphoric acid. An X-ray analysis showed that both samples (MOF-Ce-Co and MOF-Ce-Co with TiO2) had cerium and cobalt particles, however, MOF-Ce-Co with TiO2 had an additional peak at 56º, indicating that presence of TiO2 (Anatase). Hence, the improved performance of the treated MOF is the result from functionalization. This project was funded by NASA Advanced STEM Training and Research (ASTAR) Fellowship.