In-Situ Electrodeposition of Nickel on a Biocathode to Enhance Methane Production from Carbon Dioxide in a Microbial Electrosynthesis System

This study demonstrates the continuous conversion of CO2 to CH4 in a laboratory-scale Microbial Electrosynthesis System (MES). The introduction of a Ni salt at 0.2 g L-1 into the cathode influent stream improved the CO2 conversion. After the introduction of the Ni salt at an applied voltage of 2.8 V, the MES with the carbon-felt cathode reached a CH4 production of 422 ± 36 mL d-1 (0.81 L Lc -1 d-1), which was 39 ± 12% higher than that of this system before the Ni salt was introduced. Additionally, when the dissolved Ni salt was removed from the influent solution, the MES performance remained unchanged, thus confirming the in-situ deposition of Ni on the carbon-felt cathode and its catalytic effect.