Abstract: The current climate emergency has intensified interest in technologies aimed at mitigating greenhouse gas emissions, particularly carbon dioxide (CO2). Among these, CO2 capture, storage, and utilization (CCUS) technologies are gaining increasing importance. This work focuses on the electrochemical conversion of CO2 into value-added products, particularly alcohols, due to their economic relevance, exploring metal-organic frameworks (MOFs) as catalytic cathode materials. Cu-MOF-74, Cu-BTC MOF, Mg-MOF-74, and Ni-MOF-74 were evaluated as cathodic catalysts for the electrocatalytic reduction of CO2 using 0.5 M KHCO3 as the electrolyte. Ni- MOF-74 showed the best performance toward CH3OH, achieving a Faradaic Efficiency (FE) of 15.31% at -1.5 V vs. Ag/AgCl and an Energy Consumption (EC) of 2.35·103 kWh·kmol-1. C2H5OH was also obtained simultaneously, reaching a FE of 31.12% and an EC of 4.63·103 kWh·kmol- 1 at -1.3 V vs. Ag/AgCl. Subsequent experiments evaluated system efficiency by coupling these MOFs with a non-precious metal-based anode, a Ni-Fe foam. Mg-MOF-74 and Ni-MOF-74 were used in paired experiments, as they showed higher activity than the Cu-based MOFs toward alcohol production. The highest CH3OH FE (9.77%) was achieved using Ni-MOF-74 at -1.3 V, reaching a promising FE of 84.55% and an EC of 512.91 kWh·kmol-1. Although overall EC decreased in the full-cell configuration, a shift in selectivity from CH3OH to C2H5OH was observed.

Autoría

Descargar referencia