Abstract
Controlling the physical and chemical properties of alloy nanoparticles (NPs) is an important approach to optimize NP catalysis. Unlike other tuning knobs, such as size, shape, and composition, crystal structure has received limited attention and not been well understood for its role in catalysis. This deficiency is mainly due to the difficulty in synthesis and fine-tuning of the NPs' crystal structure. Here, Exemplifying by AuCu alloy NPs with face centered cubic (fcc) and face centered tetragonal (fct) structure, we demonstrate a remarkable difference in phase segregation and catalytic performance depending on the crystal structure. During the thermal treatment in air, the Cu component in fcc-AuCu alloy NPs segregates more easily onto the alloy surface as compared to that in fct-AuCu alloy NPs. As a result, after annealing at 250 °C in air for 1 h, the fcc- and fct-AuCu alloy NPs are phase transferred into Au/CuO and AuCu/CuO core/shell structures, respectively. More importantly, this variation in heterostructures introduces a significant difference in CO adsorption on two catalysts, leading to a largely enhanced catalytic activity of AuCu/CuO NP catalyst for CO oxidation. The same concept can be extended to other alloy NPs, making it possible to fine-tune NP catalysis for many different chemical reactions.
| Original language | English |
|---|---|
| Pages (from-to) | 8846-8854 |
| Number of pages | 9 |
| Journal | Journal of the American Chemical Society |
| Volume | 139 |
| Issue number | 26 |
| DOIs | |
| State | Published - Jul 5 2017 |
Funding
H.Z. J.Z., P.Z., and S.D. were supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Chemical Sciences, Geosciences, and Biosciences Division. Electron microscopy work was performed at the Center for Nanophase Materials Science at ORNL, which is sponsored by the Scientific User Facilities Division DOE-BES. W.Z., Y.G., and G.L. appreciate the financial support from the National Key Basic Research Program of China (2013CB933200), the National Key Research and Development Program of China (2016YFC0204300) 111 project (B08021), and the Fundamental Research Funds for the Central Universities (222201717003). Y.G. thanks the National Natural Science Foundation of China (21571061).
| Funders | Funder number |
|---|---|
| Scientific User Facilities Division DOE-BES | |
| U.S. Department of Energy | |
| Office of Science | |
| Basic Energy Sciences | |
| Chemical Sciences, Geosciences, and Biosciences Division | |
| National Natural Science Foundation of China | 21571061 |
| National Key Research and Development Program of China | 2013CB933200, 2016YFC0204300 |
| Fundamental Research Funds for the Central Universities | 222201717003 |
| Higher Education Discipline Innovation Project | B08021 |