Lattice engineering of AuPd@Pt core–shell icosahedra for highly efficient electrocatalytic ethanol oxidation

Abstract

Lattice engineering is a powerful strategy not only to optimize electrocatalytic performances, but also to deepen the understanding of electrocatalytic mechanisms. Lattice engineering can be effectively achieved in core–shell nanocrystals owing to the lattice mismatch of heterostructures. Herein, we constructed three kinds of icosahedra consisting of Au₇₃Pd₂₇@Pt, Au₆₆Pd₃₄@Pt and Pd@Pt core–(interlayer)–shell by a seed-mediated method. The introduction of an ultrathin Pd interlayer in the Au₆₆Pd₃₄@Pt icosahedra enables us to separately identify the strain effect and ligand effect. The specific activities towards the EOR of these icosahedra are in the sequence Au₇₃Pd₂₇@Pt > Au₆₆Pd₃₄@Pt > Pd@Pt, indicating that both the ligand effect and strain effect caused by Au can enhance the activity of Pt towards the EOR. The in situ FTIR studies confirm that the EOR processes on these icosahedra are all dominated by the C2 pathway, and hence we ascribe the enhancements of EOR activities to the faster kinetics of the C2 pathway by producing acetate or acetaldehyde.