Synthesis and Characterization of Catalytically Active Au Core─Pd Shell Nanoparticles Supported on Alumina
Journal article, 2022

A two-step seeded-growth method was refined to synthesize Au@Pd core@shell nanoparticles with thin Pd shells, which were then deposited onto alumina to obtain a supported Au@Pd/Al2O3 catalyst active for prototypical CO oxidation. By the strict control of temperature and Pd/Au molar ratio and the use of l-ascorbic acid for making both Au cores and Pd shells, a 1.5 nm Pd layer is formed around the Au core, as evidenced by transmission electron microscopy and energy-dispersive spectroscopy. The core@shell structure and the Pd shell remain intact upon deposition onto alumina and after being used for CO oxidation, as revealed by additional X-ray diffraction and X-ray photoemission spectroscopy before and after the reaction. The Pd shell surface was characterized with in situ infrared (IR) spectroscopy using CO as a chemical probe during CO adsorption-desorption. The IR bands for CO ad-species on the Pd shell suggest that the shell exposes mostly low-index surfaces, likely Pd(111) as the majority facet. Generally, the IR bands are blue-shifted as compared to conventional Pd/alumina catalysts, which may be due to the different support materials for Pd, Au versus Al2O3, and/or less strain of the Pd shell. Frequencies obtained from density functional calculations suggest the latter to be significant. Further, the catalytic CO oxidation ignition-extinction processes were followed by in situ IR, which shows the common CO poisoning and kinetic behavior associated with competitive adsorption of CO and O2 that is typically observed for noble metal catalysts.


Yanyue Feng

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Andreas Schaefer

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Anders Hellman

Chalmers, Physics, Chemical Physics

Mengqiao Di

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Hanna Härelind

Chalmers, Chemistry and Chemical Engineering

Matthias Bauer

Padernborn University

Per-Anders Carlsson

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry


07437463 (ISSN) 15205827 (eISSN)

Vol. 38 42 12859-12870

Synergistic development of X-ray techniques and applicable thin oxides for sustainable chemistry

Swedish Research Council (VR) (2017-06709), 2018-04-04 -- 2021-12-31.

Subject Categories

Inorganic Chemistry

Materials Chemistry

Other Chemistry Topics

Driving Forces

Sustainable development


Chalmers Materials Analysis Laboratory

Areas of Advance

Materials Science





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