Upgrading CO 2 into acetate on Bi 2 O 3 @carbon felt integrated electrode via coupling electrocatalysis with microbial synthesis

[摘要] Upgrading of atmospheric CO2 into high-value-added acetate using renewable electricity via electrocatalysis solely remains a great challenge. Here, inspired by microbial synthesis via biocatalysts, we present a coupled system to produce acetate from CO2 by bridging inorganic electrocatalysis with microbial synthesis through formate intermediates. A 3D Bi2O3@CF integrated electrode with an ice-sugar gourd shape was fabricated via a straightforward hydrothermal synthesis strategy, wherein Bi2O3 microspheres were decorated on carbon fibers. This ice-sugar gourd-shaped architecture endows electrodes with multiple structural advantages, including synergistic contribution, high mass transport capability, high structural stability, and large surface area. Consequently, the resultant Bi2O3@CF exhibited a maximum Faradic efficiency of 92.4% at −1.23 V versus Ag/AgCl for formate generation in 0.5 M KHCO3, exceeding that of Bi2O3/CF prepared using a conventional electrode preparation strategy. Benefiting from the high formate selectivity, unique architecture, and good biocompatibility, the Bi2O3@CF electrode attached with enriched CO2-fixing electroautotrophs served as a biocathode. As a result, a considerable acetate yield rate of 0.269 ± 0.009 g L−1 day−1 (a total acetate yield of 3.77 ± 0.12 g L−1 during 14-day operation) was achieved in the electrochemical–microbial system equipped with Bi2O3@CF.

[学科分类] 电力

[关键词] acetate;Bi2O3@CF;CO2 conversion;electrocatalysis–microbial synthesis;formate