Pd, Ag and Bi carbon-supported electrocatalysts as electrochemical multifunctional materials for ethanol oxidation and dopamine determination. (1st October 2022)

• Record Type: Journal Article
• Authors: Orzari, Luiz Otávio; Assumpção, Mônica Helena Marcon Teixeira; Nandenha, Julio; Neto, Almir Oliveira; Junior, Luiz Humberto Marcolino; Bergamini, Marcio; Janegitz, Bruno Campos
• Is Part Of: Electrochimica acta. Volume 428(2022)
• Publication Date: 2022-10-01
• Subjects: Ternary electrocatalysts -- Ethanol oxidation -- Electrochemical sensor -- Dopamine -- Multifunctional material; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2022.140932
• Languages: English
• ISSNs: 0013-4686

Abstract

Highlights: Pd, Ag, Bi and C composites were extensively characterized and investigated. Ternary electrocatalysts were applied as multifunctional materials for two different electrochemistry areas: catalysis and sensors. For fuel cell applications, PdAgBi/C presented interesting behavior with relatively low production cost. Dopamine was determined with two different mechanisms: direct oxidation and metal-catechol complexation. Abstract: This manuscript describes the investigation towards the multifunctional synthesis, characterization, and application of different Pd, Ag and Bi-carbon black supported electrocatalysts in two different fields in electrochemistry: fuel cells and electrochemical sensors. Throughout morphological and electrochemical characterizations, comprising scanning and transmission electron microscopies, X-ray powder diffraction, electrochemical impedance spectroscopy, and cyclic voltammetry techniques, the materials were characterized to better understand their properties towards proposed applications. Afterward, the materials were employed for ethanol oxidation in alkaline media, with investigations by chronoamperometry, cyclic voltammetry, and by closing a direct alkaline fuel cell, which the Pd50 Ag45 Bi05 /C composite presented attractive ethanol catalysis behavior, with a maximum power density of 19.70 mW cm −2, at 30.59 mA cm −2 . Also, the proposed device was applied for dopamine determination by square wave voltammetry. In this sense, two linear behaviors, respectively ranging from 0.2 to 1.0 and 4.0 to 40 μmol L −1 were obtained, due to two distinctive mechanisms. This higher activity has been attributed to the synergism among the used metals and proportions contributing to the bifunctional and electronic effects. As synthetic samples investigations were accomplished, data reinforces the proposed material as a possible interfacing composite in electrochemistry.