Confinement strategy to boost the compatibility of hybrid microbial-inorganic catalysis for highly efficient CO2 reduction

Hybrid microbial-inorganic catalysis is a promising technology for CO2 conversion to multi-carbon chemicals. However, incompatibility between inorganic catalysts and microorganisms remains a bottleneck. Herein, confinement strategy was employed for synthesizing inorganic hydrogen evolution reaction catalysts aiming simultaneously achieving superior performance and enhanced biocompatibility. Firstly, confining Ni nanoparticles in carbon nanotubes (Ni@CNTs) exhibited low overpotential and remarkable stability in microbial medium. Further, DFT results revealed that the adsorption of intermediate OOH* was attenuated and resulted in suppressed reactive oxygen species production. Besides, leaching Ni2+ was also significantly decreased. Moreover, comparative transcriptomics results indicated that genes related to polyhydroxybutyrate synthesis in Cupriavidus necator H16 were significantly upregulated, when coupled with Ni@CNTs cathodes. Eventually, Ni@CNTs and C. necator H16 were integrated into a hybrid catalysis system and converted CO2 to polyhydroxybutyrate. This study provides a strategy for designing hybrid microbial-inorganic catalysis systems.