Kinetics and adsorption calculations: insights into the MgO-catalyzed detoxification of simulants of organophosphorus biocides

Autor(es):Mostrar menos -

Almerindo, I, Gizelle ; Buratto, Suelen C. ^[1] ; Wanderlind, Eduardo H. ^{[2, 1]} ; Nicolazi, Lucas M. ^[1] ; Sangaletti, Patricia ^[1] ; Medeiros, Michelle ^[1] ; Schneider, Felipe S. S. ^[1] ; Caramori, Giovanni F. ^[1] ; Parreira, Renato L. T. ^[3] ; Micke, Gustavo A. ^[1] ; Fiedler, Haidi D. ^[1] ; Nome, Faruk ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Santa Catarina UFSC, Dept Quim, BR-88040900 Florianopolis, SC - Brazil

^[2] Univ Campinas UNICAMP, Inst Chem, BR-13083970 Campinas, SP - Brazil

^[3] Univ Franca, Nucleo Pesquisas Ciencias Exatas & Tecnol, BR-14404600 Franca, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF MATERIALS CHEMISTRY A; v. 8, n. 36, p. 19011-19021, SEP 28 2020.
• Citações Web of Science: 2

Resumo

We report the targeted decomposition of the organophosphate methyl paraoxon by means of its transesterification with 1-propanol catalyzed by magnesium oxide. Catalyst characterization by energy dispersive X-ray fluorescence (EDXRF), nitrogen adsorption/desorption measurements (BET and BJH methods), and temperature programmed desorption of CO2(CO2-TPD) showed that the employed MgO presents properties favorable for the methyl paraoxon adsorption and transesterification to occur. A thorough kinetic investigation showed that rate enhancements up to 3 x 10(6)-fold can be achieved in comparison with the spontaneous propanolysis of the substrate, and that the material can be used in additional cycles without loss of catalytic activity, with the catalyst recovery achieved through a simple washing procedure. Energies for adsorption of 1-propanol and methyl paraoxon onto a MgO model surface were obtained by density functional theory calculations, which showed that the latter displays a stronger affinity for the catalyst surface, and that the reaction should proceed with methyl paraoxon and 1-propanol molecules juxtapositioned at adjacent Mg(2+)sites, with nucleophilic and electrophilic centersca.2.4 angstrom away from each other. Additionally, MgO also promoted rate enhancements up to 5 x 10(4)-fold in the propanolysis of a further range of representative phosphate triesters, and in most of the cases the final transesterified products are trialkyl phosphates structurally related to a family of flame-retardants. The results thus provide insights into the development of novel systems for the targeted conversion of organophosphorus compounds into value-added products by employing simple, highly efficient, and low-cost metal oxide catalysts. (AU)

• Processo FAPESP: 19/07899-5 - Desenvolvimento de Sistemas Catalíticos Interfaciais para Reações Orgânicas Baseados em Agregados de Sais Complexos Decorados com Nanopartículas Metálicas
• Beneficiário: Eduardo Hillmann Wanderlind
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado