Abstract
Encapsulation of metal nanoparticles within oxide materials has been shown as an effective strategy to improve activity, selectivity, and stability in several catalytic applications. Several approaches have been proposed to encapsulate nanoparticles, such as forming core-shell structures, growing ordered structures (zeolites or metal-organic frameworks) on nanoparticles, or directly depositing support materials on nanoparticles. Here, a general nanocasting method is demonstrated that can produce diverse encapsulated metal@oxide structures with different compositions (Pt, Pd, Rh) and multiple types of oxides (Al2O3, Al2O3-CeO2, ZrO2, ZnZrOx, In2O3, Mn2O3, TiO2) while controlling the size and dispersion of nanoparticles and the porous structure of the oxide. Metal@polymer structures are first prepared, and then the oxide precursor is infiltrated into such structures and the resulting material is calcined to form the metal@oxide structures. Most Pt@oxides catalysts show similar catalytic activity, demonstrating the availability of surface Pt sites in the encapsulated structures. However, the Pt@Mn2O3 sample showed much higher CO oxidation activity, while also being stable under aging conditions. This work demonstrated a robust nanocasting method to synthesize metal@oxide structures, which can be utilized in catalysis to finely tune metal-oxide interfaces.
Original language | English |
---|---|
Journal | Advanced Materials |
DOIs | |
State | Accepted/In press - 2024 |
Funding
C.Z., J.O., and M.S. contributed equally to this work. This work was primarily supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences, under contract no. DE\u2010SC0022197. Additional support was provided by the National Science Foundation under grant 1956300 (J.O.) and by the Novo Nordisk Center for CO Research (Aarhus University) (C.Z.). M.L.S. acknowledges support from a TomKat Postdoctoral Fellowship in Sustainable Energy from the TomKat Center at Stanford University. Work at the Molecular Foundry was supported by the Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE\u2010AC02\u201005CH11231. Microscopy was partially performed at the Center for Nanophase Materials Sciences (CNMS), a US\u2010DOE Office of Science User Facility at Oak Ridge National Laboratory. Part of this work was performed at the Stanford Nano Shared Facilities (SNSF), supported by the National Science Foundation under award ECCS\u20102026822. 2
Keywords
- catalysts
- encapsulation
- interfaces
- metal-support interaction
- nanoparticles
- porous oxides
- stability