NiFeSn Alloy-Enhanced Microbial Electrosynthesis for Carbon Dioxide Conversion to Butyric and Caproic Acids

An efficient mixed anaerobic microbial consortium capable of producing short and medium-chain fatty acids from carbon dioxide (CO2) and hydrogen (H2) was developed through open-culture cultivation under a CO2/H2 atmosphere combined with the serial transfer technique to promote the growth of acetogenic and chain-elongating bacteria. Subsequently, this enrichment was used to inoculate laboratory-scale microbial electrosynthesis (MES) cells that were continuously fed with gaseous CO2 as the only carbon source. To improve the CO2 conversion rate and facilitate electricity-dependent chain elongation, a novel three-dimensional conductive polylactate (cPLA) cathode coated with a NiFeSn alloy was employed in one MES cell, while another (Control) MES cell was equipped with a carbon felt cathode.