New insights into the electrochemical conversion of CO2 to oxalate at stainless steel 304L cathode

New insights into the electrochemical conversion of CO2 to oxalate at stainless steel 304L cathode

[Display omitted] •Zinc oxalate synthesized in a batch reactor at 2 bar pressure with an average Faradaic efficiency of 73.9%.•Pure oxalic acid extracted from zinc oxalate with 58.2 % efficiency using ester hydrolysis process.•Low water content in the electrolyte solution ∼37 ppm and optimised curre...

Full description

Saved in:
Bibliographic Details
Published in:Journal of CO2 utilization Vol. 36; pp. 105 - 115
Main Authors: Subramanian, Siddhartha, Athira, K.R., Anbu Kulandainathan, M., Senthil Kumar, S., Barik, R.C.
Format: Journal Article
Language:English
Published: Elsevier Ltd 01-02-2020
Subjects:
Carbon dioxide
Electroreduction
Oxalic acid
Sacrificial anode
SS 304L alloy
Sacrificial anode
SS 304L alloy
Oxalic acid
Electroreduction
Carbon dioxide
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:[Display omitted] •Zinc oxalate synthesized in a batch reactor at 2 bar pressure with an average Faradaic efficiency of 73.9%.•Pure oxalic acid extracted from zinc oxalate with 58.2 % efficiency using ester hydrolysis process.•Low water content in the electrolyte solution ∼37 ppm and optimised current density of 15 mA/cm2 enhances oxalate formation. Electrochemical conversion of CO2 to value added chemicals is a promising route for its utilization and mitigation from atmosphere. Nevertheless, an industrial process involving CO2 electroreduction is yet to be a reality and requires further studies on improving the existing processes. In the present work, we report new insights into the electrochemical conversion of CO2 to zinc oxalate at SS 304 L cathode in acetonitrile in the presence of a sacrificial Zn anode. The influence of current density, water content in the electrolyte solution and pressure on product selectivity were evaluated. In addition, oxalic acid synthesis from zinc oxalate was studied using ester hydrolysis process. Our results showed that the product yield is affected due to CO2 reduction to carbonate, decomposition of acetonitrile to cyanide and glycolate formed due to partial reduction of oxalate. Experiments performed in a batch reactor at 2 bar pressure showed that an average Faradaic efficiency of 73.9% can be obtained for zinc oxalate. A yield of 58.1% was obtained for the extraction of oxalic acid. Both zinc oxalate and oxalic acid obtained from this process were compared with commercially available products to confirm its purity.
ISSN:2212-9820
2212-9839
DOI:10.1016/j.jcou.2019.10.011