Microwave-Assisted Synthesis of Pt/SnO<sub>2</sub> for the Catalytic Reduction of 4-Nitrophenol to 4-Aminophenol
Izabela Đurasović,
Goran Štefanić,
Goran Dražić,
Robert Peter,
Zoltán Klencsár,
Marijan Marciuš,
Tanja Jurkin,
Mile Ivanda,
Sándor Stichleutner,
Marijan Gotić
Affiliations
Izabela Đurasović
Laboratory for Molecular Physics and Synthesis of New Materials, Division of Materials Physics, Ruđer Bošković Institute, Bijenička c. 54, 10000 Zagreb, Croatia
Goran Štefanić
Laboratory for Molecular Physics and Synthesis of New Materials, Division of Materials Physics, Ruđer Bošković Institute, Bijenička c. 54, 10000 Zagreb, Croatia
Goran Dražić
National Institute of Chemistry, Hajdrihova 19, SI-1001 Ljubljana, Slovenia
Robert Peter
Department of Physics, University of Rijeka, Radmile Matejčić 2, 51000 Rijeka, Croatia
Zoltán Klencsár
Nuclear Analysis and Radiography Department, Centre for Energy Research, 1121 Budapest, Hungary
Marijan Marciuš
Division of Materials Chemistry, Ruđer Bošković Institute, Bijenička c. 54, 10000 Zagreb, Croatia
Tanja Jurkin
Radiation Chemistry and Dosimetry Laboratory, Division of Materials Chemistry, Ruđer Bošković Institute, Bijenička c. 54, 10000 Zagreb, Croatia
Mile Ivanda
Laboratory for Molecular Physics and Synthesis of New Materials, Division of Materials Physics, Ruđer Bošković Institute, Bijenička c. 54, 10000 Zagreb, Croatia
Sándor Stichleutner
Nuclear Analysis and Radiography Department, Centre for Energy Research, 1121 Budapest, Hungary
Marijan Gotić
Laboratory for Molecular Physics and Synthesis of New Materials, Division of Materials Physics, Ruđer Bošković Institute, Bijenička c. 54, 10000 Zagreb, Croatia
In this study, we present a new approach for the synthesis of Pt/SnO2 catalysts using microwave radiation. Pt(IV) and Sn(IV) inorganic precursors (H2PtCl6 and SnCl4) and ammonia were used, which allowed the controlled formation of platinum particles on the anisotropic SnO2 support. The synthesized Pt/SnO2 samples are mesoporous and exhibit a reversible physisorption isotherm of type IV. The XRD patterns confirmed the presence of platinum maxima in all Pt/SnO2 samples. The Williamson-Hall diagram showed SnO2 anisotropy with crystallite sizes of ~10 nm along the c-axis (00l >) and ~5 nm along the a-axis (h00 >). SEM analysis revealed anisotropic, urchin-like SnO2 particles. XPS results indicated relatively low average oxidation states of platinum, close to Pt metal. 119Sn Mössbauer spectroscopy indicated electronic interactions between Pt and SnO2 particles. The synthesized samples were used for the catalytic reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) in the presence of excess NaBH4. The catalytic activity of the Pt/SnO2 samples for the reduction of 4-NP to 4-AP was optimized by varying the synthesis parameters and Pt loading. The optimal platinum loading for the reduction of 4-NP to 4-AP on the anisotropic SnO2 support is 5 mol% with an apparent rate constant k = 0.59 × 10–2 s–1. The Pt/SnO2 sample showed exceptional reusability and retained an efficiency of 81.4% after ten cycles.
