Sustainable production of formic acid by electrolytic reduction of gaseous carbon dioxide

A tin (Sn) nanostructure has been applied to a gas diffusion electrode for the direct electro-reduction of carbon dioxide (CO2) in a zero-gap electrolytic cell. A Sn catalyst layer was evenly applied to a carbon substrate by a controlled spraying technique and the efficient catalytic conversion of gas-phase CO2 to formic acid (HCOOH) demonstrated. We observed that the overall mean faradaic efficiency towards HCOOH remained above 5.0% over the entire reduction time. In addition, due to its compact configuration and surroundings at near ambient conditions the approach described is promising in both modularity and scalability. Sustainable energy sources such as solar, wind, or geothermal electricity could be used as a power source to minimize the large-scale operating cost.