Selectivity of Cobalt-Based Non-Platinum Oxygen Reduction Catalysts in the Presence of Methanol and Formic Acid

TLDR: In this article, the reaction selectivity of non-Pt based fuel cell oxygen reduction catalysts is studied in mixed methanol/O2 and formic acid/O 2 environments.

Abstract: The reaction selectivity of non-Pt based fuel cell oxygen reduction catalysts is studied in mixed methanol/O2 and formic acid/O2 environments. Technologically relevant fuel cell reaction processes are elucidated by combining experiment and theory. Structure-to-property correlations are established utilizing a mutivariant analysis technique (MVA) for catalyst surface species as determined by XPS and electrochemical performance parameters obtained in mixed reactant systems for a family of non-Pt fuel cell catalysts. Computations at the density-functional-theory (DFT) level support our experimental findings. We used first-principle simulations to explore the interactions of cobalt functionalized graphene with H2O2, O2, CO, and N2. We find that N2 and O2 adsorb as molecular species. In contrast H2O2 decomposes to form a strongly bound Co(OH)2 complex. O2 is intermediate, the oxygen−oxygen bond lengthens by ∼10% as compared to the gas phase and its binding energy (per atom) is less strong as compared to H2O2. ...