Improved chlorate production with platinum nanoparticles deposited on fluorinated activated carbon cloth electrodes

• Main Authors: María Isabel Alvarado Ávila, Esteban Toledo-Carrillo, Joydeep Dutta
• Format: Article
• Language: English
• Published: Elsevier 2020-12-01
• Series: Cleaner Engineering and Technology
• Subjects: Sodium chlorate; Electrolysis; Current efficiency; Carbon-based catalyst; Fluorine doping; Platinum nanoparticles
• Online Access: http://www.sciencedirect.com/science/article/pii/S2666790820300161

Sodium chlorate is one of the main oxidizing agents used in the wood industry due to their capability of use as an elemental chlorine-free (CEF) bleaching. A simple way to produce chlorates is by the electrolysis of an aqueous sodium chloride (NaCl) solution. In the present study activated carbon cloth electrodes (ACC) modified with fluorine and platinum nanoparticles (Pt–F/ACC and Pt/ACC) were used as one of the electrodes. Electrofluorination was used for fluorination of the anodes and polyol method was used for the synthesis of platinum nanoparticles. Chlorate production using a typical solution of 100 ​g/l of sodium chloride (NaCl) and 2 ​g/l sodium chromate (Na2Cr2O7) and an applied current of 0.540 ​A was studied. Prior to the electrolysis assays, the microstructural properties of the electrodes were characterized by scanning electron microscopy and surface modifications and bonding using infra-red (FTIR) spectroscopy. Electrochemical properties were determined using cyclic voltammetry (CV), linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques. Interaction between fluorine (F) and platinum (Pt) on the electrode leads to an improvement of the electrocatalytic properties for chlorine evolution as observed from the increase in the current efficiency from 37.5% at 78.5% after 150 ​min of continuous electrolysis using Pt–F/ACC anodes. The results suggest that modified activated carbon material is an attractive and economical alternative as electrodes for chlorate production.