Proceedings of MATSUS Spring 2024 Conference (MATSUS24)
Publication date: 18th December 2023
Nowadays, the CO2 electroreduction reaction (CO2RR) is considered an attractive way to convert CO2 into feedstocks and renewable energy vectors [1]. However, such a conversion is limited by two main factors: lack of selectivity to carbon-based products and need of high overpotentials to activate the CO2 molecule. One possible way to overcome such limitations is to use catalysts that promote CO2 reduction and show poor activity towards hydrogen evolution (main by-product) [2].
In this work, we have studied the CO2RR to formate on tin-based catalysts and the effect of the magnesium. The alloy was obtained by thermal annealing using the Mg and Sn metallic powders as a precursor [3]. The catalyst was characterized by X-Ray diffraction and electron microscopy (SEM, TEM and EDX) before and after the electrochemistry (EC). The alloy presents an amorphous morphology and a size change can be observed before and after the EC. We investigated the activity of these material for electrocatalytic CO2RR via Linear sweep voltammetry (LSV) and cycling voltammetry (CV) experiments, in the presence of CO2. We also performed long-term chronoamperometry tests to identify the reaction products, finding a high selectivity towards formate. From electrochemical and analytical data, we were able to determine the most promising phases to carry out this reaction.