Energy demand is constantly increasing and the use of fossil fuels causes an accumulation of carbon dioxide (CO2) which is an important environmental problem that needs to be solved. A promising solution to this problem would be the electrochemical reduction of CO2 to useful products, using the surplus of electricity from renewable sources. This would be a way of storing this excess of electricity in chemical bonds. However, this has not reached high efficiency and selectivity needed for establishing its use. For this process, the CO2 is usually dissolved in an aqueous electrolyte. This thesis proposes the new approach, using Deep Eutectic Solvents (DES) which would capture a higher concentration of CO2 helping to make the whole process more efficient. However, not all salt mixtures reach the eutectic point and therefore, the solvents formed are a low-transition temperature mixtures (LTTMs) of the selected salts. Experimental work was performed to find out if these solvents can be used for electrochemical carbon dioxide reduction. Non-reported LTTMs were synthetized; they were formed with mixtures of the hydrogen bond donor citric acid (CA), fructose (F) and diethanolamine (DEA) with the hydrogen bond acceptor tetrabutylammonium chloride (TBA-Cl) and different quantities of water, which was found necessary to carry out electrochemistry since the solvents formed were too viscous, and this water has an important effect in the electrocatalytic reduction of CO2 as proton source and charge carrier. These solvents were characterized electrochemically, performing studies to find out on which metallic surface they behave better (wider working potential window, low degree of decomposition and adsorption) and how different water quantities affect this process. These studies were performed using cyclic voltammetry. From this, it was seen that the solvents are more stable during electrochemical process in presence of copper. Moreover, the solvent formed by DEA:TBA-Cl:H2O in the molar proportions 1:1:1,375 was found to have interesting features that resemble CO2 reduction. As result, this solvent was further analysed using electrochemical in-situ Fourier-Transformed Infrared (FTIR) spectroscopy in surface-enhanced attenuated total reflectance configuration. With this, it was seen that the carbon dioxide was captured by the solvent and that there are visible changes when applying potential. Remarkably, the data shows the formation of a dimer OCCO on the Cu electrode surface, stabilized by the solvent. This project shows for the first time the electrochemical reduction of CO2 in LTTMs, evaluating different solvents, metals and water quantities. Determining that the carbon dioxide reduction is possible with the solvent DEA:TBA-Cl:H2O in the molar proportions 1:1:1,375 in a copper polycrystalline electrode.