The development of a gas-feeding CO2 fuel cell using direct hydrazine oxidation reaction

Electrochemical carbon dioxide (CO2) reduction has attracted attention for converting CO2 into value-added products at room temperature. Conventional electrochemical CO2 reduction methods require external energy because of the high overpotential of the oxygen evolution reaction (OER). To overcome the limitation of the OER, we propose a gaseous CO2 reduction system that uses an aqueous hydrazine (N2H4) oxidation reaction. In this study, the N2H4-CO2 fuel cell is proposed for the simultaneous generation of electricity with CO2 conversion. During the operation of the aqueous N2H4/gas-feeding CO2 fuel cell, a power density of 20.31 mW/cm2 was obtained and 49.20 % of CO2 was converted to CO at the Ag cathode. We also evaluated the correlation between the flow rate of the anolyte and the hydrophobicity of the Ag cathode in terms of cell performance.

Automated summary

An gaseous CO2 reduction system using an aqueous hydrazine oxidation reaction is proposed for converting CO2 into value-added products. This system demonstrates high power density and CO2 conversion rate. The correlation between the flow rate of the anolyte and the hydrophobicity of the Ag cathode in terms of cell performance is also evaluated.