TY - JOUR

T1 - Breaking with the Principles of Coreduction to Form Stoichiometric Intermetallic PdCu Nanoparticles

AU - Mathiesen, Jette K.

AU - Bøjesen, Espen D.

AU - Pedersen, Jack K.

AU - Kjær, Emil T.S.

AU - Juelsholt, Mikkel

AU - Cooper, Susan

AU - Quinson, Jonathan

AU - Anker, Andy S.

AU - Cutts, Geoff

AU - Keeble, Dean S.

AU - Thomsen, Maria S.

AU - Rossmeisl, Jan

AU - Jensen, Kirsten M.Ø.

N1 - Funding Information: The authors are grateful to the Villum Foundation for financial support through a Villum Young Investigator grant (VKR00015416). The authors acknowledge support from the Danish Ministry of Higher Education and Science (Structure of Materials in Real Time (SMART) grant) and the Danish National Research Foundation Center for High Entropy Alloy Catalysis (DNRF 149). E.D.B. acknowledges funding from the Carlsberg Foundation (Grant CF18‐0705). M.S.T. thanks the Villum Foundation (grant#14922) for support. The Danish Research Council is acknowledged for covering travel expenses in relation to the synchrotron experiment (DanScatt). The authors acknowledge the staff of beamline 11‐ID‐B at APS and I15‐1 at DIAMOND for experimental assistance. This work was carried out with the support of Diamond Light Source, instrument I15‐1 (proposal EE20187). Use of the Advanced Photon Source, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science by Argonne National Laboratory, was supported by the U.S. DOE under Contract No. DE‐AC02‐06CH11357. Publisher Copyright: © 2022 The Authors. Small Methods published by Wiley-VCH GmbH.

PY - 2022

Y1 - 2022

N2 - Intermetallic nanoparticles (NPs) have shown enhanced catalytic properties as compared to their disordered alloy counterparts. To advance their use in green energy, it is crucial to understand what controls the formation of intermetallic NPs over alloy structures. By carefully selecting the additives used in NP synthesis, it is here shown that monodisperse, intermetallic PdCu NPs can be synthesized in a controllable manner. Introducing the additives iron(III) chloride and ascorbic acid, both morphological and structural control can be achieved. Combined, these additives provide a synergetic effect resulting in precursor reduction and defect-free growth; ultimately leading to monodisperse, single-crystalline, intermetallic PdCu NPs. Using in situ X-ray total scattering, a hitherto unknown transformation pathway is reported that diverges from the commonly reported coreduction disorder–order transformation. A Cu-rich structure initially forms, which upon the incorporation of Pd(0) and atomic ordering forms intermetallic PdCu NPs. These findings underpin that formation of stoichiometric intermetallic NPs is not limited by standard reduction potential matching and coreduction mechanisms, but is instead driven by changes in the local chemistry. Ultimately, using the local chemistry as a handle to tune the NP structure might open new opportunities to expand the library of intermetallic NPs by exploiting synthesis by design.

AB - Intermetallic nanoparticles (NPs) have shown enhanced catalytic properties as compared to their disordered alloy counterparts. To advance their use in green energy, it is crucial to understand what controls the formation of intermetallic NPs over alloy structures. By carefully selecting the additives used in NP synthesis, it is here shown that monodisperse, intermetallic PdCu NPs can be synthesized in a controllable manner. Introducing the additives iron(III) chloride and ascorbic acid, both morphological and structural control can be achieved. Combined, these additives provide a synergetic effect resulting in precursor reduction and defect-free growth; ultimately leading to monodisperse, single-crystalline, intermetallic PdCu NPs. Using in situ X-ray total scattering, a hitherto unknown transformation pathway is reported that diverges from the commonly reported coreduction disorder–order transformation. A Cu-rich structure initially forms, which upon the incorporation of Pd(0) and atomic ordering forms intermetallic PdCu NPs. These findings underpin that formation of stoichiometric intermetallic NPs is not limited by standard reduction potential matching and coreduction mechanisms, but is instead driven by changes in the local chemistry. Ultimately, using the local chemistry as a handle to tune the NP structure might open new opportunities to expand the library of intermetallic NPs by exploiting synthesis by design.

KW - formation mechanism

KW - in situ X-ray total scattering

KW - intermetallic nanoparticles

KW - synthesis by design

U2 - 10.1002/smtd.202200420

DO - 10.1002/smtd.202200420

M3 - Journal article

C2 - 35460216

AN - SCOPUS:85128728217

VL - 6

JO - Small Methods

JF - Small Methods

SN - 2366-9608

IS - 6

M1 - 2200420

ER -