20.500.12556/DiRROS-23644 Catalytically Active Oxidized ▫$PtO_x$▫ Species on ▫$SnO_2$▫ Supports Synthesized via Anion Exchange Reaction for 4-Nitrophenol Reduction An anion exchange-assisted technique was used for the synthesis of platinum-decorated SnO2 supports, providing nanocatalysts with enhanced activity for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). In this study, a series of SnO2 supports, namely SnA (synthesized almost at room temperature), SnB (hydrothermally treated at 180 ◦C), and SnC (annealed at 600 ◦C), are systematically investigated, all loaded with 1 mol% Pt from H2PtCl6 under identical mild conditions. The chloride ions from the SnCl4 precursors were efficiently removed via a strong-base anion exchange reaction, resulting in highly dispersed, crystalline ~5 nm cassiterite SnO2 particles. All Pt/SnO2 composites displayed mesoporous structures with type IVa isotherms and H2-type hysteresis, with SP1a (Pt on SnA) exhibiting the largest surface area (122.6 m2/g) and the smallest pores (~3.5 nm). STEM-HAADF imaging revealed well-dispersed PtOx domains (~0.85 nm), while XPS confirmed the dominant Pt4+ and Pt2+ species, with ~25% Pt0 likely resulting from photoreduction and/or interactions with Sn–OH surface groups. Raman spectroscopy revealed three new bands (260–360 cm−1) that were clearly visible in the sample with 10 mol% Pt and were due to the vibrational modes of the PtOx species and Pt-Cl bonds introduced due the addition and hydrolysis of H2PtCl6 precursor. TGA/DSC analysis revealed the highestmass loss for SP1a (~7.3%), confirming the strong hydration of the PtOx domains. Despite the predominance of oxidized PtOx species, SP1a exhibited the highest catalytic activity (kapp = 1.27 × 10−2 s−1) and retained 84.5% activity for the reduction of 4-NP to 4-AP after 10 cycles. This chloride-free low-temperature synthesis route offers a promising and generalizable strategy for the preparation of noble metal-based nanocatalysts on oxide supports with high catalytic activity and reusability. platinum SnO2 anion exchange Dowex 550 catalyst 4-nitrophenol 119Sn Mössbauer materiali nanomateriali platina katalizatorji true false true Angleški jezik Slovenski jezik © 2025 by the authors. Licensee MDPI, Basel, Switzerland. Neznano 2025-09-18 13:36:57 2025-09-18 13:49:31 2025-10-24 03:54:44 0000-00-00 00:00:00 2025 0 0 Nasl. z nasl. zaslona; Opis vira z dne 17. 9. 2025; str. 1-28 iss. 15, ǂ[article no.] ǂ1159 Vol. 15 Jul. 2025 0000-00-00 Zaloznikova Objavljeno apc 0000-00-00 0000-00-00 2025-07-01 620.1/.2 2079-4991 10.3390/nano15151159 249312003 https://www.mdpi.com/2079-4991/15/15/1159 1 cac17549-9483-11f0-9bb7-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=34995 RAZ_Durasovic_Izabela_2025.pdf RAZ_Durasovic_Izabela_2025.pdf 1 EAF86E1DA694CBCCDD900649C7BDB7FF b88b8d7e5023ee541e308af8a549202369478c3ae4ed18b47bdce256431cc385 37528ca0-9485-11f0-9bb7-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=34996 Kemijski inštitut 0 0 0