Bioadaptive Ni Single Atoms Unlock High Rate Microbial Electrosynthesis of Isopropanol from CO2: Article No. 1639

Hybrid systems that integrate electrochemical CO2 reduction with microbial upgrading offer a viable route to high value organic compounds from CO2 at ambient conditions. However, electrocatalyst deactivation in microbial growth media remains a key barrier, limiting efficiency and increasing cost. Here we show that a bioadaptive single-atom nickel catalyst (Ni SAC), coupled with genetically engineered Clostridium ljungdahlii, enables robust electrosynthesis of isopropanol (IPA) from CO2 via a CO-mediated pathway. Instead of relying on H2 as an electron carrier, the system applies high-rate CO formation in complex growth media, maintaining a tunable CO Faradaic efficiency up to 92%, which is 9.4 to 52.7 times greater than conventional Ag catalysts. This performance supports stable IPA production at current density of 10.8 A/m2 and production rate of 161.3 mg/L/day. In situ Raman and X-ray absorption spectroscopy, together with theoretical calculations, indicate that the Ni SAC can resist competing organic adsorption and retain its coordination structure during CO2 reduction in bioelectrolytes, providing a mechanistic basis for the catalyst stability and integrated process performance.