Advanced heterostructure of Pd nanosheets@Pt nanoparticles boosts methanol electrooxidation

Heterostructures have emerged as elaborate structures to improve catalytic activity owing to their combined surface and distinct inverse interface. However, fabricating advanced nanocatalysts with facet-dependent interface remains an unexploited and promising area. Herein, we render the controlled growth of Pt nanoparticles (NPs) on Pd nanosheets (NSs) by regulating the reduction kinetics of Pt2+ with solvents. Specifically, the fast reduction kinetic makes the Pt NPs uniformly deposited on the Pd NSs (U-Pd@Pt HS), while the slow reduction kinetic leads to the preferential growth of Pt NPs on the edge of the Pd NSs (E-Pd@Pt HS). Density functional theory calculations demonstrate that Pd (111)-Pt interface in U-Pd@Pt HS induces the electron-deficient status of Pd substrates, triggering the d-band center downshift and amplifying the Pd-Pt intermetallic interaction. The synergy between the electronic effect and interfacial effect facilitates the removal of poisonous intermediates on U-Pd@Pt HS. By virtue of the Pd NSs@Pt NPs interface, the heterostructure achieves exceptional methanol oxidation reaction activity as well as improved durability. This study innovatively proposes heterostructure engineering with facet-dependent interfacial modulation, offering instructive guidelines for the rational design of versatile heterocatalysts.