Enhanced Electrocatalytic Activities of Perovskite Electrocatalysts for the Oxidation of Small Molecules By Active Site Variation

Thursday, 1 June 2017: 10:20
Grand Salon B - Section 7 (Hilton New Orleans Riverside)
K. J. Stevenson (Skolkovo Institute of Science and Technology), R. Forslund (The University of Texas at Austin), and K. P. Johnston (University of Texas at Austin)
The electrooxidation of urea and other small molecules has attracted considerable attention the anodic reaction for the electrochemical generation of hydrogen due to the lower electrochemical potential required to drive the reaction. Nickel and nickel-based materials have shown comparable activities to precious metal catalysts for the electrooxidation of urea and other small molecules in alkaline conditions. By incorporating nickel into the perovskite structure as well as derivatives of the perovskite structure, higher oxidation states of nickel active sites can be achieved, leading to increased catalytic activities at a fraction of the cost of other nickel-rich materials. While these materials are shown to be stable at low overpotentials, in depth mechanistic studies reveal restructuring of the catalyst surface and apparent deactivation due to poisoning from CO2 upon extended cycling, an occurrence that may be extended to describe catalyst deactivation in other nickel-based materials.