Facile preparation of hollow PT-and PtIr-nanostructures with spiky surface for the electro-oxidation of ammonia

In this paper, we described the facile preparation of Pt-and PtIr-based hollow nanostructures (Pt-Am and PtIr-Am), which could be achieved through a coreduction of precious metal complexes with ammine ligands and Ni ions that were reduced to form an in situ sacrificial template. For a comparative study, other types of Pt and Ir precursors with chloride ligands, i.e., Pt-Cl and PtIr-Cl, were also employed for the preparation of Pt and PtIr-based nanostructures. In constrast to Pt-Am and PtIr-Am, both Pt-Cl and PtIr-Cl showed typical aggregated small particles. The surface composition and element distribution were also affected by the type of metal precursors employed. Owing to a dilution effect of Ir or Ni on the surface of the Pt, Pt-Cl and PtIr-Cl showed a lower electrochemically active surface area and poor catalytic performance in the electro-oxidation of ammonia. Owing to a high EAS combined with the synergic effect of Ir, PtIr-Am delivered the highest oxidation current among the catalysts studied in this work.