Paired electrolysis for simultaneous generation of synthetic fuels and chemicals

Centralized production of fuels and platform chemicals from non-fossil fuel resources using renewable energy is indispensable to curb the ever increasing global warming. To realise this vision, a distributed model based on small scale reactors needs to be constructed. In this context, electrolysers performing water splitting and carbon dioxide reduction to produce sustainable fuels carry paramount industrial importance. All these electrolysers use water oxidation as anodic half-reaction which produces oxygen having a low economic value and a higher overpotential requirement. This increases the input voltage of electrolysers. The product value and energy efficiency of these electrolysers can be further enhanced if the electrochemical hydrogen evolution and carbon dioxide reduction can be paired with alternative oxidation reactions such as biomass oxidation, electro-organic synthesis, etc. , which are thermodynamically more favorable than water oxidation. This review summarizes the importance of these paired electrolysis processes for simultaneous production of fuels and value-added platform chemicals from hybrid electrolysers along with a discussion of optimization of process parameters for paired electrolysis. Replacing anodic oxygen evolution of water splitting or carbon dioxide reduction by electro-organic oxidation increases their product-value and energy efficiency.