TY - JOUR
T1 - Optimization and continuous-flow operation of electrochemically mediated selective formate separation by polyvinyl ferrocene/graphene oxide electrodes
AU - Polat, Sevgi
AU - Kortlever, Ruud
AU - Eral, Hüseyin Burak
PY - 2023
Y1 - 2023
N2 - Electrochemical carbon dioxide (CO2) reduction is a promising route to convert intermittent renewable energy into fuels and valuable chemical products. Separation of CO2 reduction products by ion-selective electrochemical technology may play a decisive role in the pursuit of commercially viable CO2 reduction processes. Selective separation of formate, one of the main CO2 reduction products, is assessed in the present study in an electrochemical flow cell with symmetric redox-active polyvinyl ferrocene (PVF) functionalized graphene oxide (GO) electrodes. First, experimental parameters such as the PVF/GO ratio, sonication time, and ultrasonic amplitude, were optimized in the electrode preparation process to improve the formate adsorption efficiency on a lab scale (1 × 2 cm electrodes) under static conditions. The electrochemical and morphological characteristics of the electrodes were investigated by cyclic voltammetry and scanning electron microscopy. To demonstrate continuous-flow operation, an electrosorption flow cell (8 × 8 cm) providing inline measurements was constructed. The flow cell results showed selectivity at > 5.5 toward the removal of formate from an electrolyte containing perchlorate at an excess of 30 times the normal value. The performance of the electrosorption cell was also tested using a mixture of methanol, ethanol, formate, and acetaldehyde produced in a CO2 reduction electrolyzer. In this demonstration, formate separation was achieved with a selectivity of > 4.0. The results suggest that the optimized design of the electrochemical cell and operation conditions of the flow platform pave the way for scaling up selective formate separation with PVF/GO electrodes.
AB - Electrochemical carbon dioxide (CO2) reduction is a promising route to convert intermittent renewable energy into fuels and valuable chemical products. Separation of CO2 reduction products by ion-selective electrochemical technology may play a decisive role in the pursuit of commercially viable CO2 reduction processes. Selective separation of formate, one of the main CO2 reduction products, is assessed in the present study in an electrochemical flow cell with symmetric redox-active polyvinyl ferrocene (PVF) functionalized graphene oxide (GO) electrodes. First, experimental parameters such as the PVF/GO ratio, sonication time, and ultrasonic amplitude, were optimized in the electrode preparation process to improve the formate adsorption efficiency on a lab scale (1 × 2 cm electrodes) under static conditions. The electrochemical and morphological characteristics of the electrodes were investigated by cyclic voltammetry and scanning electron microscopy. To demonstrate continuous-flow operation, an electrosorption flow cell (8 × 8 cm) providing inline measurements was constructed. The flow cell results showed selectivity at > 5.5 toward the removal of formate from an electrolyte containing perchlorate at an excess of 30 times the normal value. The performance of the electrosorption cell was also tested using a mixture of methanol, ethanol, formate, and acetaldehyde produced in a CO2 reduction electrolyzer. In this demonstration, formate separation was achieved with a selectivity of > 4.0. The results suggest that the optimized design of the electrochemical cell and operation conditions of the flow platform pave the way for scaling up selective formate separation with PVF/GO electrodes.
KW - Cell design
KW - Electrochemical separation
KW - Formate
KW - Optimization
KW - Resource recovery
UR - http://www.scopus.com/inward/record.url?scp=85171884409&partnerID=8YFLogxK
U2 - 10.1016/j.cej.2023.146169
DO - 10.1016/j.cej.2023.146169
M3 - Article
AN - SCOPUS:85171884409
SN - 1385-8947
VL - 475
JO - Chemical Engineering Journal
JF - Chemical Engineering Journal
M1 - 146169
ER -