Electrochemical conversion of CO2 to formic acid using a Sn based electrode: A critical review on the state-of-the-art technologies and their potential

The electrochemical conversion of carbon dioxide is considered one of the most promising strategies to convert waste-CO2 into value-added chemicals. This review focuses on the synthesis of formic acid/formate in aqueous electrolyte using Sn-based cathodes; this material is considered relatively cheap and shows promising results in terms of faradaic efficiency. In order to be suitable at an industrial scale, the process should present simultaneously high current densities, faradaic efficiencies close to 100%, high concentrations of formic acid and long-term stability. Analysing the main results reported in the literature, it was observed that to date further studies are necessary to achieve this outcome. Several strategies that can be used to overcome the main bottlenecks of the process were presented and critically reviewed. Finally, to evaluate the main factors that affect the scalability of the process on an industrial scale, a technical-economic overview was discussed. (C) 2021 Elsevier Ltd. All rights reserved.