Optimization and continuous-flow operation of electrochemically mediated selective formate separation by polyvinyl ferrocene/graphene oxide electrodes

Optimization and continuous-flow operation of electrochemically mediated selective formate separation by polyvinyl ferrocene/graphene oxide electrodes

Polat, S. (TU Delft Complex Fluid Processing; Marmara University)
Kortlever, R. (TU Delft Large Scale Energy Storage)
Eral, H.B. (TU Delft Complex Fluid Processing)

2023

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.

Cell design
Electrochemical separation
Formate
Optimization
Resource recovery

http://resolver.tudelft.nl/uuid:fd514f73-b798-49c1-aab7-b65cd6c80f0a

https://doi.org/10.1016/j.cej.2023.146169

1385-8947

Chemical Engineering Journal, 475

Institutional Repository

journal article

© 2023 S. Polat, R. Kortlever, H.B. Eral