Heterogeneous Cu–Pd binary interface boosts stability and mass activity of atomic Pt clusters in the oxygen reduction reaction

Abstract

A ternary metallic CuPdPt nanocatalyst (NC) is synthesized using a wet chemical reduction method, which is sequentially designed, in the presence of acid treated carbon nanotubes. This NC is a nanocrystal with a configuration of a Cu@Pd core and atomic Pt clusters (∼9 wt%) on the top (Cu@Pd/Pt). A residual current of 92.6%, 5.2 times higher than that of commercial Pt catalysts (at 0.85 V vs. RHE), is retained after 40 000 cycles of an accelerated degradation test (ADT). Atomic and electronic structure analyses show that such exclusive stability mainly results from electron localization at Pt clusters in heterogeneous interfaces of the Cu-Pd core. Most importantly, we develop a robust ternary NC, which shows outstanding MA, superior chemical durability, and ∼90 wt% lower Pt loading than commercial Pt NCs in the oxygen reduction reaction.

H2Reduction Annealing Induced Phase Transition and Improvements on Redox Durability of Pt Cluster-Decorated Cu@Pd Electrocatalysts in Oxygen Reduction Reaction

“…Low-magnification image in Figure c and histogram show that Cu@Pd/Pt is grown in a broad size distribution ranging from 2 to 6 nm with an average particle size of 3.8 nm, whereas in the case of Cu@Pd/Pt-H, particle size distribution range is noted from 7 to 11 nm owing to particle agglomeration and Cu 3 Pt/Cu 1– x Pd x alloy formation. For comparison, crystal structural analyses of Cu@Pt and Pd@Pt NCs have been considered …”

“…For comparison, crystal structural analyses of Cu@Pt and Pd@Pt NCs have been considered. 26 Phase segregation, lattice strain, and average coherent length (D avg ) of experimental NCs are further revealed by XRD analysis, and the corresponding structural parameters are summarized in Table 1. Composition for Pd phase in experimental NCs is estimated by using Vegard's law, and the qualitative index for the preferential facet is determined by intensity ratios of H (111) /H (hkl) (H (111) and H (200) refer, respectively, to intensities for diffraction peaks of ( 111) and (200) facets).…”

“…However, noble-metal usage is limited by formation of monolayer shell thickness in such configurations. To further improve metal utilization and enhance electron relocation potential at the heterogeneous binary interface with a lower amount of Pt usage, surface decoration of strong electronegative and active sub-nanometer Pt clusters in cluster-in-cluster structured NCs is a possible strategy . Recently, researchers also developed an effective strategy to control the depth of decorating clusters .…”

“…To further improve metal utilization and enhance electron relocation potential at the heterogeneous binary interface with a lower amount of Pt usage, surface decoration of strong electronegative and active sub-nanometer Pt clusters in cluster-in-cluster structured NCs is a possible strategy. 26 Recently, researchers also developed an effective strategy to control the depth of decorating clusters. 27 Those Pt clusters extract electrons from the heterogeneous binary interface of inner clusters by strong electronegative force and local lattice during redox reaction.…”

Conformational Effects of Pt-Shells on Nanostructures and Corresponding Oxygen Reduction Reaction Activity of Au-Cluster-Decorated NiOx@Pt Nanocatalysts

“…Meanwhile, Pt forms an unconformable shell, which protects the core crystal from corrosion and shares ORR pathways, including O 2 splitting and relocation kinetics of O-atoms, and thus avoids highly energetic intermediates and their associated kinetic penalties. Our previous work demonstrated a facile approach to trigger ORR activity via Pt-decorated core-shell structures [31,32,33,34,35]. Those ternary metallic NCs consisting of lower dosages of Pt showed distinct activity towards ORR facilitation but with reduced fabrication costs.…”