Enhancing Oxygen Reduction Reaction Catalytic Activity Using a Sub-Stoichiometric CaTiO3-delta Additive

Platinum scarcity and its high cost have led to the requirement of alternative materials catalysing the oxygen reduction reaction (ORR), which is the main rate-determining step occurring in electrochemical devices, including metal-air batteries and fuel cells. We report a study on a sub-stoichiometric calcium titanate (CaTiO3-?, CTO) compound used as promoter for the ORR in order to reduce the Pt loading and improve its electrocatalytic activity. Composite catalysts based on Pt/C with different amounts of CTO were prepared and their activity was investigated by rotating disk electrode (RDE). The obtained results proved a higher catalytic activity for the composite electrode, with respect to pure Pt/C, in terms of electrochemically active surface area, oxygen reduction current density, onset potential and stability