Title :

Characterization of Carbon Anode Protected by Low Boron Level: An Attempt To Understand Carbon–Boron Inhibitor Mechanism

Author(s) :

Ishak, Ramzi [Auteur]
Natural Sciences and Engineering Research Council of Canada - NSERC (CANADA)
Laroche, Gaétan [Auteur]
Lamonier, Jean-Francois [Auteur]
Unité de Catalyse et Chimie du Solide - UMR 8181 [UCCS]
Ziegler, Donald P. [Auteur]
Alamdari, Houshang [Auteur]
Natural Sciences and Engineering Research Council of Canada - NSERC (CANADA)

Journal title :

ACS Sustainable Chemistry & Engineering

Abbreviated title :

ACS Sustainable Chem. Eng.

Volume number :

5

Pages :

6700-6706

Publisher :

ACS

Publication date :

2017-07-09

English keyword(s) :

Air reactivity
Carbon anode
Impregnation
Boron oxide
ToF-SIMS
Carbon gasification
Aluminum production

HAL domain(s) :

Chimie/Catalyse

English abstract : [en]

Several chemical reactions occur during the electrolysis of alumina in the Hall–Héroult process resulting in a significant overconsumption of the carbon anode. Carbon oxidation with oxygen is one of these reactions. The ...
Show more >Several chemical reactions occur during the electrolysis of alumina in the Hall–Héroult process resulting in a significant overconsumption of the carbon anode. Carbon oxidation with oxygen is one of these reactions. The inhibition of this reaction by the application of protective layers on the anode can be an effective technique to reduce carbon consumption. Boron impregnation was shown to suppress this reaction. In this study, very low boron content has been impregnated on the anode, and several characterization methods have been performed to understand the protection mechanism of such a low boron concentration during the oxidation reaction of anodes. An air reactivity test of boron-impregnated anodes has been performed at temperatures between 400 and 600 °C. The samples were characterized using XPS, Raman spectroscopy, XRD, XRF, porosimetry, and thermogravimetric analysis (TGA). TGA revealed that the total number of interactions between oxygen atoms and carbon active sites was reduced, decreasing the pre-exponential factor. Time-of-flight secondary ion mass spectroscopy (ToF-SIMS) has been employed as a highly sensitive surface characterization method to identify chemical forms of boron on the anode. It has been confirmed that boron blocks active sites of carbon by creating boron–carbon bonds, thus reducing the interaction of carbon active sites with oxygen.Show less >

Language :

Anglais

Peer reviewed article :

Oui

Audience :

Internationale

Popular science :

Non

Administrative institution(s) :

ENSCL
CNRS
Centrale Lille
Univ. Artois
Université de Lille

Collections :

• Unité de Catalyse et Chimie du Solide (UCCS) - UMR 8181

Research team(s) :

Remédiation et matériaux catalytiques (REMCAT)

Submission date :

2019-09-25T14:05:37Z
2021-03-29T14:21:07Z