Solid-State Dispersions of Platinum in the SnO2 and Fe2O3 Nanomaterials.

Edi Radin,Goran Dražić,Tanja Jurkin,Matea Raić,Goran Štefanić,Nikola Baran,Anđela Pustak,Marijan Gotić,Ivan Marić

doi:10.3390/nano11123349

Edi Radin, Goran Dražić + Show 7 more

Open Access

https://doi.org/10.3390/nano11123349

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Abstract

The dispersion of platinum (Pt) on metal oxide supports is important for catalytic and gas sensing applications. In this work, we used mechanochemical dispersion and compatible Fe(II) acetate, Sn(II) acetate and Pt(II) acetylacetonate powders to better disperse Pt in Fe2O3 and SnO2. The dispersion of platinum in SnO2 is significantly different from the dispersion of Pt over Fe2O3. Electron microscopy has shown that the elements Sn, O and Pt are homogeneously dispersed in α-SnO2 (cassiterite), indicating the formation of a (Pt,Sn)O2 solid solution. In contrast, platinum is dispersed in α-Fe2O3 (hematite) mainly in the form of isolated Pt nanoparticles despite the oxidative conditions during annealing. The size of the dispersed Pt nanoparticles over α-Fe2O3 can be controlled by changing the experimental conditions and is set to 2.2, 1.2 and 0.8 nm. The rather different Pt dispersion in α-SnO2 and α-Fe2O3 is due to the fact that Pt4+ can be stabilized in the α-SnO2 structure by replacing Sn4+ with Pt4+ in the crystal lattice, while the substitution of Fe3+ with Pt4+ is unfavorable and Pt4+ is mainly expelled from the lattice at the surface of α-Fe2O3 to form isolated platinum nanoparticles.

Highlights

Accepted: 7 December 2021The nanomaterials based on noble metal nanoparticles and semiconducting transition metal oxides have found applications in electrochemistry, photochemistry, biosensing, catalysis and gas sensing
The dispersion of platinum over α-SnO2 is clearly different from the Pt dispersion over α-Fe2 O3
EDXS results (Figure 5) have shown that Sn, O and Pt elements are homogeneously dispersed in α-SnO2, indicating the formation of a (Pt,Sn)O2 solid solution

Summary

Introduction

The nanomaterials based on noble metal nanoparticles and semiconducting transition metal oxides have found applications in electrochemistry, photochemistry, biosensing, catalysis and gas sensing. The Pt nanoparticles dispersed on the non-expensive. SnO2 or Fe2 O3 supports have been used in various catalytic reactions or in gas sensing applications. Chen et al [1] hydrothermally synthesized a Pt/Fe2 O3 nanocomposite catalyst with facet and defect structure for the catalytic oxidation of formaldehyde under ambient conditions. Lang et al [2] reported the synthesis of a thermally stable Pt single-atom catalyst dispersed on an Fe2 O3 support. Experimental and computational modeling studies showed that the reducibility of the iron oxide is crucial for the anchoring of the isolated Pt atoms. Ren et al [3] controlled the dispersion of platinum on Fe2 O3 and

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Discussion

Conclusion