Synthesis of Pt decorated manganese oxide (▫${\rm MnO}_2/{\rm Mn}_5{\rm O}_8$▫) nanorods and their catalytic activity for the reduction of 4-nitrophenol to 4-aminophenol

Marić, Ivan (author), Šoltić, Monika (author), Dražić, Goran (author), van Spronsen, Matthijs A. (author), Štefanić, Goran (author), Ivanda, Mile (author), Held, Georg (author), Jurkin, Tanja (author), Bohinc, Klemen (author), Gotić, Marijan (author)

α-MnO2 nanorods (NRs) were synthesized by microwave irradiation and used as supports for platinum nanoparticles by wet impregnation with Pt(acac)2 as precursor. XRD analysis revealed that the samples without platinum (sample MP0) and with 1 % platinum (sample MP1) contained tetragonal α-MnO2. Samples with 3 % (sample MP3) and 5 % (sample MP5) of platinum contained monoclinic Mn5O8 in addition to α-MnO2, with Mn5O8 dominating in sample MP5. Rietveld analysis showed that the lattice parameters of α-MnO2 increased slightly with Pt loading. SEM and STEM showed that higher Pt loadings resulted in shorter nanorods and different sizes and dispersions of PtNPs on their surface. XPS results showed a decrease in Pt(IV) and Pt(II) concentration with Pt loading, while Pt(0) increased. NEXAFS results showed the presence of Mn(II) in MP3 and MP5, which is consistent with XRD results detecting Mn5O8. The catalytic activity of the Pt/α-MnO2 nanorods was tested in the catalytic reduction of 4-nitrophenol to 4-aminophenol. MP1, with the lowest platinum content, exhibited the highest mass normalized rate constant kapp/mPt of 1.8 × 104 s−1 g−1. The study suggests that the presence of Pt(IV) is not a limiting factor for the catalytic reduction of 4-NP to 4-AP.

• Language: English
• Keywords: manganese oxides, microwave synthesis, platinum, reducible supports, wet-impregnation, 4-nitrophenol reduction
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: ZF - Faculty of Health Sciences
• Publication status: Published
• Publication version: Version of Record
• Year: 2024
• Number of pages: 12 str.
• Numbering: Vol. 649, art. 159091
• PID: 20.500.12556/RUL-153558
• UDC: 544
• ISSN on article: 1873-5584
• DOI: 10.1016/j.apsusc.2023.159091
• COBISS.SI-ID: 180932611
• Publication date in RUL: 15.01.2024

Record is a part of a journal

• Title: Applied Surface Science
• Publisher: North-Holland
• ISSN: 1873-5584
• COBISS.SI-ID: 22979333

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: manganovi oksidi, mikrovalovna sinteza, platina, reducibilni nosilci, mokra impregnacija, redukcija 4-nitrofenola

Projects

• Funder: HRZZ - Croatian Science Foundation
• Funding programme: Croatian Science Foundation (CSF)
• Project number: IP-2019-04-1195
• Name: Platinum decorated iron tin oxide solid solutions for hydrogen gas sensing