Data/hora: 22/06/2024 04:34:35

Biblioteca(s): | Embrapa Instrumentação.
Data corrente: | 22/03/2022
Data da última atualização: | 23/01/2024
Autoria: | SILVA, P. F. da; GOMES, B. F.; LOBO, C. M. S.; CARMO, M.; ROTH, C.; COLNAGO, L. A.
Afiliação: | LUIZ ALBERTO COLNAGO, CNPDIA.
Título: | Composite graphite epoxy electrodes for in situ electrochemistry coupling with high resolution NMR.
Ano de publicação: | 2022
Fonte/Imprenta: | ACS Omega 2022, v. 7, 2022.
Páginas: | 4991-5000
DOI: | https://doi.org/10.1021/acsomega.1c05823
Idioma: | Inglês
Conteúdo: | The in situ coupling between electrochemistry and spectrometric techniques can help in the identification and quantification of the compounds produced and consumed during electrochemical reactions. The combination of electrochemistry with nuclear magnetic resonance is quite attractive in this respect, but it has some challenges to be addressed, namely, the reduction in the quality of the NMR signal when the metallic electrodes are placed close to or in the detection region. Since NMR is not a passive technique, the convective effect of the magnetic force (magnetoelectrolysis), which acts by mixing the solution and increasing the mass transport, has to be considered. In seeking to solve the aforementioned problems, we developed a system of miniaturized electrodes inside a 5 mm NMR tube (outer diameter); the working and counter electrodes were prepared with a mixture of graphite powder and epoxy resin. To investigate the performance of the electrodes, the benzoquinone reduction to hydroquinone and the isopropanol oxidation to acetone were monitored. To monitor the alcohol oxidation reaction, the composite graphite−epoxy electrode (CGEE) surface was modified through platinization. The electrode was efficient for in situ monitoring of the aforementioned reactions, when positioned 1 mm above the detection region of the NMR spectrometer. The magnetoelectrolysis effect acts by stirring the solution and increases the reaction rate of the reduction of benzoquinone, because this reaction is limited by mass transport, while no effect on the reaction rate is observed for the isopropanol oxidation reaction.
Palavras-Chave: | Electrochemical reactions; Magnetoelectrolysis; Nuclear magnetic resonance.
Categoria do assunto: | --
URL: | http://ainfo.cnptia.embrapa.br/digital/bitstream/item/232809/1/P-Composite-Graphite8722Epoxy-Electrodes-for-In-Situ-Electrochemistry.pdf
Registro original: | Embrapa Instrumentação (CNPDIA)
Exemplares: | CNPDIA - (17944-1) - UPC - AP - DD - PROCI.22/13 -  - 2022/13 - DIS