A Review of the Use of Electrolytic Cells for Energy and Environmental Applications

There is a significant push to reduce carbon dioxide (CO2) emissions and develop low-cost fuels from renewable sources to replace fossil fuels in applications such as energy production. As a result, CO2 conversion has gained widespread attention as it can reduce the accumulation of CO2 in the atmosphere and produce fuels and valuable industrial chemicals, including carbon monoxide, alcohols, and hydrocarbons. At the same time, finding ways to store energy in batteries or energy carriers such as hydrogen (H2) is essential. Water electrolysis is a powerful technology for producing high-purity H2, with negligible emission of greenhouse gases, and compatibility with renewable energy sources. Additionally, the electrolysis of organic compounds, such as lignin, is a promising method for localised H2 production, as it requires lower cell voltages than conventional water electrolysis. Industrial wastewater can be employed in those organic electrolysis systems due to their high organic content, decreasing industrial pollution through wastewater disposal. Electrocoagulation, indirect electrochemical oxidation, anodic oxidation, and electro-Fenton are effective electrochemical methods for treating industrial wastewater. Furthermore, bioenergy technology possesses a remarkable potential for producing H2 and other value-added chemicals (e.g., methane, formic acid, hydrogen peroxide), along with wastewater treatment. This paper comprehensively reviews these approaches by analysing the literature in the period 2012–2022, pointing out the high potential of using electrolytic cells for energy and environmental applications.