TY - JOUR

T1 - Pd-Au Nanostructured Electrocatalysts with Tunable Compositions for Formic Acid Oxidation

AU - Plaza-Mayoral, Elena

AU - Pereira, Ines Jordao

AU - Dalby, Kim Nicole

AU - Jensen, Kim Degn

AU - Chorkendorff, Ib

AU - Falsig, Hanne

AU - Sebastian-Pascual, Paula

AU - Escudero-Escribano, Maria

PY - 2022

Y1 - 2022

N2 - Green transition requires strategies to develop active and stable nanomaterials for energy conversion. We describe the preparation of Pd-Au bimetallic nanocatalysts using a surfactant-free electrodeposition method in a deep eutectic solvent (DES) and test their electrocatalytic performance in the formic acid oxidation reaction (FAOR). We use choline chloride and urea DES to tune the compositions of Pd and Au in the bimetallic nanostructures, as well as their morphologies and active surface areas. We measure the increase in electrochemically active surface area (ECSA) of the prepared Pd-Au bimetallic surfaces by Cu underpotential deposition (UPD). Our results indicate a surface area increase of 5-to 12-fold compared to Pd and PdAu extended polycrystalline electrodes. We observe that the higher acti v i t y of Pd-Au nanostructures is principally due to their increased active area. Our results also reveal that Pd-Au nanostructures with ca. 50% of Pd and Au display the best activity and stabi l i t y in relation to the Pd mass loading, proving the synergy between Pd and Au in t h e bimetallic catalyst. We highlight that an in-depth analysis of the ECSA, as well as surface and electronic structure effects in bimetallic nanostructures, is crucial for the rationalization of their catalytic properties.

AB - Green transition requires strategies to develop active and stable nanomaterials for energy conversion. We describe the preparation of Pd-Au bimetallic nanocatalysts using a surfactant-free electrodeposition method in a deep eutectic solvent (DES) and test their electrocatalytic performance in the formic acid oxidation reaction (FAOR). We use choline chloride and urea DES to tune the compositions of Pd and Au in the bimetallic nanostructures, as well as their morphologies and active surface areas. We measure the increase in electrochemically active surface area (ECSA) of the prepared Pd-Au bimetallic surfaces by Cu underpotential deposition (UPD). Our results indicate a surface area increase of 5-to 12-fold compared to Pd and PdAu extended polycrystalline electrodes. We observe that the higher acti v i t y of Pd-Au nanostructures is principally due to their increased active area. Our results also reveal that Pd-Au nanostructures with ca. 50% of Pd and Au display the best activity and stabi l i t y in relation to the Pd mass loading, proving the synergy between Pd and Au in t h e bimetallic catalyst. We highlight that an in-depth analysis of the ECSA, as well as surface and electronic structure effects in bimetallic nanostructures, is crucial for the rationalization of their catalytic properties.

KW - electrodeposition

KW - electrocatalysis

KW - formic acid oxidation

KW - deep eutectic solvent

KW - palladium-gold nanostructures

KW - SINGLE-CRYSTAL ELECTRODES

KW - SHAPE-DEPENDENT ELECTROCATALYSIS

KW - NOBLE-METAL ELECTRODES

KW - X-RAY PHOTOEMISSION

KW - REAL SURFACE-AREA

KW - UNDERPOTENTIAL DEPOSITION

KW - FUEL-CELL

KW - ELECTROCHEMICAL CHARACTERIZATION

KW - CARBON-MONOXIDE

KW - PALLADIUM

U2 - 10.1021/acsaem.2c01361

DO - 10.1021/acsaem.2c01361

M3 - Journal article

VL - 5

SP - 10632−10644

JO - ACS Applied Energy Materials

JF - ACS Applied Energy Materials

SN - 2574-0962

IS - 9

ER -