Electrochemical reduction of carbon dioxide to hydrocarbons

Abstract

Global accumulation of CO2 in the atmosphere has become a significant environmental challenge in the past twodecades. Global warming and climate change resulting from increasing concentrations of CO2 are of utmost concern for scientists. Converting CO2 electrochemically to value-added chemicals is currently the most practical and economically viable solution for remediating this problem. It can utilize electrical energy from intermittent sustainable sources such as solar and wind. This chapter reviews the most important principles of applied electrochemical techniques and methods for reducing CO2 to hydrocarbons, where theoretical background and related basic techniques in electrochemistry are introduced. Hence, this chapter will address the details of the most widely used electrochemical techniques as well as the main metal electrodes used in these processes and their outcomes. The techniques reported mainly include cyclic and linear sweep voltammetry, chronopotentiometry and chronoamperometry. Further, the effect of the electrode composition, electrolytic solution, temperature and hydrodynamic flow are discussed. An illustration of the conversion mechanism of CO2 to formic acid/formate, which is a major industrial product, is presented. The results for electroreduction of CO2 to formic acid/formate from different research groups are discussed. Generally, tin-based electrodes were the most promising in maximizing faradaic efficiency and current density and minimizing the energy consumption, which are the most critical factors for optimizing the electrochemical process. 2022 Elsevier Inc. All rights reserved.