Syngas production from electrochemical reduction of CO2: current status and prospective implementation

The CO2 that comes from the use of fossil fuels accounts for about 65% of the global greenhouse gas
emission, and it plays a critical role in global climate changes. Among the different strategies that have
been considered to address the storage and reutilization of CO2, the transformation of CO2 into chemicals
or fuels with a high added-value has been considered a winning approach. This transformation is able
to reduce the carbon emission and induce a “fuel switching” that exploits renewable energy sources. The
aim of this brief review is to gather and critically analyse the main efforts that have been made and
achievements that have been made in the electrochemical reduction of CO2 for the production of CO.
The main focus is on the prospective of exploiting the intrinsic nature of the electrolysis process, in which
CO2 reduction and H2 evolution reactions can be combined, into a competitive approach, to produce
syngas. Several well-established processes already exist for the generation of fuels and fine-chemicals
from H2/CO mixtures of different ratios. Hence, the different kinds of electrocatalysts and electrochemical
reactors that have been used for the CO and H2 evolution reactions have been analysed, as well as the
main factors that influence the performance of the system from the thermodynamic, kinetic and mass
transport points of view.