Autor(es)

Yamakawa, Gabriel Franco ; Ribeiro, Lara Kelly ; Reis, Roberta Yonara Nascimento ; Mascaro, Lucia Helena ; Longo, Elson ; Assis, Marcelo

• Tipo de documento: Artigo Científico
• Fonte: CATALYSIS SCIENCE & TECHNOLOGY; v. 15, n. 13, p. 12-pg., 2025-05-21.

Resumo

Sulfones are valuable compounds with diverse applications in pharmaceuticals and materials science. In this study, we present a promising approach for the efficient oxidation of sulfides to sulfones using WO3 supported on chitosan-derived carbon as a heterogeneous catalyst. The method is based on the green synthesis of WO3 particles via the coprecipitation method, followed by their impregnation onto a carbon support obtained through chitosan pyrolysis, with loadings of 10, 20, and 40% (w/w). The heterostructure of the WO3/carbon nanocomposite promotes charge separation due to interactions between the semiconductor and the pi electrons of the carbon matrix. Among the tested catalysts, the 20% WO3 composition exhibited the best performance. The optimized reaction conditions were 60 degrees C, 120 min of reaction time, 8 equivalents of oxidant (H2O2), and 10 mg of catalyst. The choice of solvent played a crucial role, with conversions exceeding 99% achieved in both acetonitrile and water. However, catalyst stability was higher in water, while deactivation in acetonitrile was attributed to WO3 leaching, as confirmed by X-ray photoelectron spectroscopy analysis. Beyond its excellent scalability, the catalytic system effectively oxidized a wide range of substrates, in particular in acetonitrile. Mechanistic investigations revealed that hydroxyl radicals (*OH) and singlet oxygen (1O2) were the primary reactive species driving the oxidation process. This work underscores the versatility and robustness of WO3/carbon catalysts for sulfide oxidation, establishing a promising platform for sustainable and efficient chemical transformations. (AU)

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• Beneficiário: Marcelo de Assis
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
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• Modalidade de apoio: Auxílio à Pesquisa - Regular
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• Modalidade de apoio: Bolsas no Brasil - Doutorado
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• Modalidade de apoio: Bolsas no Brasil - Programa Fixação de Jovens Doutores