Oxygen reduction reaction: Semi-empirical quantum mechanical and electrochemical study of Printex L6 carbon black

Author(s)

Marques Cordeiro-Junior, Paulo Jorge ^[1] ; Goncalves, Roger ^[2] ; Guaraldo, Thais Tasso ^[1] ; Paiva, Robert da Silva ^[2] ; Pereira, Ernesto Chaves ^[2] ; de Vasconcelos Lanza, Marcos Roberto ^[1]

Affiliation

^[1] Univ Sao Paulo, Sao Carlos Inst Chem, Ave Trabalhador Sao Carlense 400, BR-13566590 Sao Carlos, SP - Brazil

^[2] Univ Fed Sao Carlos, Dept Chem, BR-13565905 Sao Carlos, SP - Brazil

• Document type: Journal article
• Source: Carbon; v. 156, p. 1-9, JAN 2020.
• Web of Science Citations: 0

Abstract

Amorphous carbon black (CB) is a highly reactive material for O-2 reduction and widely employed in H2O2 generation. Most studies published have confined their investigation to few electrochemical properties of CB and its morphological and structural characterization. However, an in-depth understanding of CB properties and their effects on oxygen reduction reaction appears to be the key to making significant progress in this field. This paper describes the use of quantum mechanical semi-empirical calculations to obtain structural information and electrochemical impedance spectroscopy to access the electrochemical information of Printex L6 CB (PCL6). It is the first report of its kind in the literature. The semi-empirical results show that PCL6 electrode presents an increase in the number of hotspots due to the presence of large amount of sp(2) carbon and functional groups in its composition, which favors O-2 adsorption at lower potentials. The equilibrium distance on PCL6 electrode is closer to the distance of a double bond (C=O), reinforcing O-2 bridge-like adsorption model. Furthermore, PCL6 had proved to be thermodynamically more favourable to O-2 adsorption and requires relatively lower energy and potential (shift of 150 mV). PLC6 is found to undergo an activation process, probably associated with O-2 adsorption, prior to the beginning of reaction. (C) 2019 Elsevier Ltd. All rights reserved. (AU)

• FAPESP's process: 14/11861-0 - Development of nanostructured electrochemical sensors for the determination of antibiotics in samples of environmental interest
• Grantee: Thais Tasso Guaraldo
• Support type: Scholarships in Brazil - Post-Doctorate
• FAPESP's process: 14/50945-4 - INCT 2014: National Institute for Alternative Technologies of Detection, Toxicological Evaluation and Removal of Micropollutants and Radioactivies
• Grantee: Maria Valnice Boldrin
• Support type: Research Projects - Thematic Grants
• FAPESP's process: 11/14314-1 - Study of the modification of gas diffusion electrodes with redox catalysts for in situ electrogeneration of hydrogen peroxide (H2O2)
• Grantee: Marcos Roberto de Vasconcelos Lanza
• Support type: Regular Research Grants
• FAPESP's process: 17/10118-0 - Study and application of electrochemical technology for the analysis and degradation of endocrine interferents: materials, sensors, processes and scientific dissemination
• Grantee: Marcos Roberto de Vasconcelos Lanza
• Support type: Research Projects - Thematic Grants
• FAPESP's process: 16/01937-4 - Synthesis of binary metal oxides (Nb, Zr, Ta, Ru, Mo and Co) supported on amorphous carbon for the production of gas diffusion electrodes (GDE) for the electrosynthesis of H2O2 in situ in flow reactors.
• Grantee: Marcos Roberto de Vasconcelos Lanza
• Support type: Regular Research Grants
• FAPESP's process: 16/19612-4 - Degradation of endocrine disruptors carbofuran, methylparaben and propylparaben via electrogenerated H2O2 and associated processes (electrogenerated H2O2/UV, electro-Fenton e photoelectro-Fenton)
• Grantee: Paulo Jorge Marques Cordeiro Junior
• Support type: Scholarships in Brazil - Doctorate (Direct)