MnXWO4 nanostructure-based catalysts for single-step oxidation of cyclohexane and methane to oxygenates

TitleMnXWO4 nanostructure-based catalysts for single-step oxidation of cyclohexane and methane to oxygenates
Publication TypeJournal Article
Year of Publication2023
AuthorsPrabu, M, Manikandan, M, Samal, PParamita, Gurrala, LPrasad, Mekala, SPrasad, Archana, R, Nayak, C, Bhattacharyya, D, Jha, SN, Krishnamurty, S, Raja, T
JournalACS Applied Nano Materials
Volume6
Issue9
Pagination7245-7258
Date PublishedAPR
Type of ArticleArticle
KeywordsAdipic Acid, C-H bond activation, Cyclohexane oxidation, methane activation, MnOx chain, Redox center
Abstract

Activation of the C-H bond in cyclohexane (CYH) and methane is a crucial step to obtain desirable oxygenated products using nanostructured catalyst and is a great challenge and an efficient route to mitigate the inauspicious effects of climate change. The active sites were identified using XRD, HR-TEM, SEM, N2 sorption analysis, TPR, Raman, XPS, TGA, in situ DRIFT, XAS, etc. In optimal reaction conditions, 46% of CYH was converted into adipic acid (AA) on MnxWO4 nanostructures within 6 h. The recyclability test confirmed the catalyst heterogeneity, which revealed no appreciable loss of catalytic activity even after three consecutive reactions. In situ DRIFT study reveals that CYH is oxidized to cyclohexanone and cyclohexanol (KA oil) and is further oxidized to AA via carboxylate intermediates. DFT studies disclosed that MnOx species are responsible for the C-H activation of CYH, and the Mn2+/Mn3+ redox centers play a vital role in the absorption of KA oil to form AA. Herein, we demonstrated the significant role of the ``MnOx'' species and that adequate Lewis and Bronsted acidic sites, redox centers of (Mn2+/Mn3+), and lattice oxygen are accountable for the CYH conversion toward the AA. Additionally, we have reported the oxidation of methane to methanol (146 mu mole per gram of catalyst) in the presence of water at 75 degrees C without over-oxidation products.

DOI10.1021/acsanm.3c00319
Type of Journal (Indian or Foreign)

Foreign

Impact Factor (IF)

5.9

Divison category: 
Catalysis and Inorganic Chemistry
Database: 
Web of Science (WoS)

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