Gold-promoted structurally ordered intermetallic palladium cobalt nanoparticles for the oxygen reduction reaction

Abstract

Considerable efforts to make palladium and palladium alloys active catalysts and a possible replacement for platinum have had a marginal success. Here we report on a structurally ordered Au 10 Pd 40 Co 50 catalyst that exhibits comparable activity to conventional platinum catalysts in both acid and alkaline media. Electron microscopic techniques demonstrate that, at elevated temperatures, palladium cobalt nanoparticles undergo an atomic structural transition from core-shell to a rare intermetallic ordered structure with twin boundaries forming stable {111}, {110} and {100} facets via addition of gold atoms. The superior stability of this catalyst compared with platinum after 10,000 potential cycles in alkaline media is attributed to the atomic structural order of PdCo nanoparticles along with protective effect of clusters of gold atoms on the surface. This strategy of making ordered palladium intermetallic alloy nanoparticles can be used in diverse heterogeneous catalysis where particle size and structural stability matter.

Correlation of Surface Ag Content in AgPd Shells of Ultrasmall Core–Shell Au@AgPd Nanoparticles with Enhanced Electrocatalytic Performance for Ethanol Oxidation

“…[2][3][4][5][6] It is known that the introduction of other metals or metal oxide to form bimetallic Pd-based catalysts is the very efficient strategy to implement superior catalytic activity. [7][8][9][10][11] For instance, the presence of Au in Pd-based catalysts can efficiently remove intermediates by oxidation and thus significantly improve the catalyst resistance to poisoning for better durability. [12][13][14][15] Bimetallic particles with a unique core-shell (CS) structure can minimize the utilization of precious metal precursors, since the majority of Pd atoms is distributed at the electrochemical reaction interface.…”

Fe2N/S/N Codecorated Hierarchical Porous Carbon Nanosheets for Trifunctional Electrocatalysis

“…Among various catalysts, the NSCF 3c248 exhibited the most positive onset potential of 0.92 V versus RHE for ORR reaction, which is much close to 20% Pt/C (onset potential 0.95 V vs RHE). Furthermore, the NSCF 3c248 shows high half‐wave potential of 0.81 V versus RHE which is only 30 mV lower than state‐of‐the‐art Pt/C catalysts …”

Ultrasmall Pd‐Cu‐Pt Trimetallic Twin Icosahedrons Boost the Electrocatalytic Performance of Glycerol Oxidation at the Operating Temperature of Fuel Cells

“…To the best of our knowledge, the reported metal icosahedrons mainly focus on pure metal or bimetallic nanocrystals (Table S1, Supporting Information), there is no example of uniform trimetallic twin icosahedrons with size of ≈10 nm to be reported thus far, because the trimetallic system has much more complex factors such as the lattice mismatch, reduction potential of different metal precursors and twin‐fault energy than pure metal and bimetallic system. Besides the size and shape, the surface composition has been confirmed another critical factor affecting physical and chemical performance of nanocrystals, especially in electrocatalysis . In electrocatalysis, different kinds of atoms in the surface of nanocrystal often have different functions, sometimes, the adjacent heteroatoms would build the catalytic active sites of new functions due to the electronic effect (ligand effect and local strain effect) and /or ensemble effect, which is quite different from single metal nanocrystal …”