Gold–Copper Nanoparticles: Nanostructural Evolution and Bifunctional Catalytic Sites

• DOI: 10.1021/cm302097c
• Publication Date: 2012-12-12T16:54:03Z
• Authors: Jun Yin; Shiyao Shan; Lefu Yang; Derrick Mott; Oana Malis; Valeri Petkov; Fan Cai; Mei Shan Ng; Jin Luo; Bing H. Chen; Mark Engelhard; Chuan-Jian Zhong
• Keywords: Catalysts; OXIDE; Silica; Molecules; BIMETALLIC NANOPARTICLES; OXIDATION; 540; 01 natural sciences; Catalysis; 0104 chemical sciences; REDUCTION; SIZE; NANOCRYSTALS; X-RAY-DIFFRACTION; MOLECULAR-DYNAMICS; Catalyst activity; Nanoparticles; Nanotechnology; CU ALLOY NANOPARTICLES; Carbon monoxide; CLUSTERS; Alloying; Copper

Understanding of the atomic-scale structure is essential for exploiting unique catalytic properties any nanoalloy catalyst. This report describes novel findings an investigation nanoscale alloying gold–copper (AuCu) nanoparticles and its impact on surface functions. Two pathways have been explored formation AuCu different compositions, including wet chemical synthesis from mixed Au- Cu-precursor molecules, via evolution near melting temperatures. For precursor nanoparticles, synchrotron X-ray-based in situ real-time XRD was used to monitor structural changes, revealing reshaping toward fcc-type (particle or cube) a partial melting–resolidification mechanism. The nanoalloys supported carbon silica were characterized by high-energy XRD/atomic pair disributoin function (PDF) analyses, intriguing lattice "expanding–shrinking" phenomenon depending whether catalyst thermochemically processed under oxidative reductive atmosphere. type controllable changes found play important role determining activity catalysts monoxide oxidation reaction. tunable activities atmospheres are also discussed terms bifunctional sites oxygenated metal species oxygen activation.