TY - JOUR

T1 - Successful synthesis and thermal stability of immiscible metal Au-Rh, Au-Ir andAu-Ir-Rh nanoalloys

AU - Shubin, Yury

AU - Plyusnin, Pavel

AU - Sharafutdinov, Marat

AU - Makotchenko, Evgenia

AU - Korenev, Sergey

PY - 2017/4/25

Y1 - 2017/4/25

N2 - We successfully prepared face-centred cubic nanoalloys in systems of Au-Ir, Au-Rh and Au-Ir-Rh, with large bulk miscibility gaps, in one-run reactions under thermal decomposition of specially synthesised single-source precursors, namely, [AuEn2][Ir(NO2)6], [AuEn2][Ir(NO2)6] x [Rh(NO2)6]1-x and [AuEn2][Rh(NO2)6]. The precursors employed contain all desired metals 'mixed' at the atomic level, thus providing significant advantages for obtaining alloys. The observations using high-resolution transmission electron microscopy show that the nanoalloy structures are composed of well-dispersed aggregates of crystalline domains with a mean size of 5 ±3 nm.nergy dispersive x-ray spectroscopy and x-ray powder diffraction (XRD) measurements confirm the formation of AuIr, AuRh, AuIr0.75Rh0.25, AuIr0.50Rh0.50 and AuIr0.25Rh0.75 metastable solid solutions. In situ high-temperature synchrotron XRD (HTXRD) was used to study the formation mechanism of nanoalloys. The observed transformations are described by the 'conversion chemistry' mechanism characterised by the primary development of particles comprising atoms of only one type, followed by a chemical reaction resulting in the final formation of a nanoalloy. The obtained metastable nanoalloys exhibit essential thermal stability. Exposure to 180 °C for 30 h does not cause any dealloying process.

AB - We successfully prepared face-centred cubic nanoalloys in systems of Au-Ir, Au-Rh and Au-Ir-Rh, with large bulk miscibility gaps, in one-run reactions under thermal decomposition of specially synthesised single-source precursors, namely, [AuEn2][Ir(NO2)6], [AuEn2][Ir(NO2)6] x [Rh(NO2)6]1-x and [AuEn2][Rh(NO2)6]. The precursors employed contain all desired metals 'mixed' at the atomic level, thus providing significant advantages for obtaining alloys. The observations using high-resolution transmission electron microscopy show that the nanoalloy structures are composed of well-dispersed aggregates of crystalline domains with a mean size of 5 ±3 nm.nergy dispersive x-ray spectroscopy and x-ray powder diffraction (XRD) measurements confirm the formation of AuIr, AuRh, AuIr0.75Rh0.25, AuIr0.50Rh0.50 and AuIr0.25Rh0.75 metastable solid solutions. In situ high-temperature synchrotron XRD (HTXRD) was used to study the formation mechanism of nanoalloys. The observed transformations are described by the 'conversion chemistry' mechanism characterised by the primary development of particles comprising atoms of only one type, followed by a chemical reaction resulting in the final formation of a nanoalloy. The obtained metastable nanoalloys exhibit essential thermal stability. Exposure to 180 °C for 30 h does not cause any dealloying process.

KW - gold

KW - immiscible metal nanoalloys

KW - iridium

KW - rhodium

KW - single-source precursors

KW - thermal decomposition

KW - thermal stability

KW - SUPPORTED GOLD NANOPARTICLES

KW - ALLOY NANOPARTICLES

KW - CO

KW - HYDROGEN

KW - LOW-TEMPERATURE OXIDATION

KW - PD

KW - CATALYTIC-ACTIVITY

KW - FEPT NANOPARTICLES

KW - PHASE-DIAGRAMS

KW - BIMETALLIC NANOPARTICLES

UR - http://www.scopus.com/inward/record.url?scp=85018990276&partnerID=8YFLogxK

U2 - 10.1088/1361-6528/aa6bc9

DO - 10.1088/1361-6528/aa6bc9

M3 - Article

AN - SCOPUS:85018990276

VL - 28

JO - Nanotechnology

JF - Nanotechnology

SN - 0957-4484

IS - 20

M1 - 205302

ER -