In situ growth Ni-Cu active site on the cathode boosting the selective synthesis of butyrate in microbial electrosyntshesis

The microbial electrosynthesis (MES) converted CO2 into butyrate, which was a promising carbon resource utilization technology. However, the low electron transfer efficiency between microorganisms and the cathode severely restricted its performance. This study proposed to in-situ construct bimetallic active sites (Cu/Ni) on the surface of carbon felt (CF) by electrochemical deposition, achieving the first efficient biological conversion of CO2 into butyrate. CO2 is fixed into acetyl-[ACP] through the Wood-Ljungdahl pathway (WLP), and then acetyl-[ACP] converted into butyrate by the reverse b-oxidation (RBO) and fatty acid biosynthesis (FAB). Moreover, this also significantly enhanced the expression of functional genes related to electron transfer, energy metabolism and quorum sensing. This study provided technical assistance for optimizing the microbial-electrode interface and paved a new path for sustainable carbon capture and biocatalytic production.