A Single‐Atom Manipulation Approach for Synthesis of Atomically Mixed Nanoalloys as Efficient Catalysts

Abstract

Synthesis of well‐defined atomically mixed alloy nanoparticles on desired substrates is an ultimate goal for their practical application. Herein we report a general approach for preparing atomically mixed AuPt, AuPd, PtPd, AuPtPd NAs(nanoalloys) through single‐atom level manipulation. By utilizing the ubiquitous tendency of aggregation of single atoms into nanoparticles at elevated temperatures, we have synthesized nanoalloys on a solid solvent with CeO2 as a carrier and transition‐metal single atoms as an intermediate state. The supported nanoalloys/CeO2 with ultra‐low noble metal content (containing 0.2 wt % Au and 0.2 wt % Pt) exhibit enhanced catalytic performance towards complete CO oxidation at room temperature and remarkable thermostability. This work provides a general strategy for facile and rapid synthesis of well‐defined atomically mixed nanoalloys that can be applied for a range of emerging techniques.

Recent Progress of Single‐Atom Alloys in Heterogeneous Catalytic Reactions

“…(c) Normalized XANES spectra at the Pt L 3 ‐edge of Pt SAs, Au/Pt SAs, AuPt NAs, and Pt foil. (d) Fourier transforms of EXAFS at the Pt L 3 ‐edge spectra of Pt SAs, Au/Pt SAs, AuPt NAs, and Pt foil [21] . Reproduced from Ref.…”

“…For AuPt SAA, the complete oxidation of carbon monoxide could be achieved at room temperature and at very low noble metal content (0.2 wt % Pt and 0.2 wt % Au) (Figure 7a). During the catalytic process, due to the formation of uniform AuPt atomic alloys, the synergistic effect between Au and Pt occurred through electron transfer, which makes the D‐band center of the Pt atom closer to the Fermi level (Figure 7b–e), and at the same time, the D‐band center of Au was far away from Fermi level which led to the worse catalytic activity of Au atom, thus Pt atom was the really active center in this reaction [21] …”

“…Based on the incipient wetness impregnation method, our group developed a universal method for the synthesis of noble SAAs on the surface of ceria, such as AuPt, AuPd, PtPd, and multi‐metallic AuPtPd (Figure 3a, b). [21] Then we select the example of AuPt SAA to comprehend the synthesis process. The first key in this work is the reduction treatment of ceria in the H 2 /Ar stream at 200 °C, which uses its redox properties to produce more oxygen vacancy and Ce 3+ for the next step of preparation of SAA.…”

“…(e) The formation energy (E F ) of two paths to synthesize uniform alloys is determined by theoretical calculation and the binding energies (E bind ) of Au and Pt atoms. At 0 K, Pt binds stronger than Au does, and the formation of AuPd NA is slightly endothermic based on atoms in the bulk metal, although it is strongly exothermic based on free atoms (see Supporting Information for details) [21] . Reproduced from Ref.…”

Recent Advances of Single-Atom Metal Supported at Two-Dimensional MoS2 for Electrochemical CO2 Reduction and Water Splitting

“…Therefore, SACs have shown prominent activity in various electrochemistry processes, including CO 2 RR [16,17], oxygen evolution reaction (OER) [18,19], and hydrogen evolution reaction (HER) [20,21]. However, since the surface energy increases with the decrease in particle size, the single atoms tend to aggregate into clusters or nanoparticles [22,23], which leads to degraded functions. Hence, it is indispensable to anchor the isolated atoms onto the appropriate supports to build stable configurations with atomic distribution [24,25].…”