TY - JOUR
T1 - Porous nickel hollow fiber cathodes coated with CNTs for efficient microbial electrosynthesis of acetate from CO2 using Sporomusa ovata
AU - Bian, Bin
AU - AlQahtani, Manal Faisal
AU - Katuri, Krishna
AU - Liu, Defei
AU - Bajracharya, Suman
AU - Lai, Zhiping
AU - Rabaey, Korneel
AU - Saikaly, Pascal
N1 - KAUST Repository Item: Exported on 2021-02-19
Acknowledged KAUST grant number(s): URF/1/2985-01-01
Acknowledgements: This work was supported by the Competitive Research Grant (URF/1/2985-01-01) from the King Abdullah University of Science and Technology (KAUST). We thank Omar El Tall, a research scientist in the Core Lab at KAUST, for helping with the CO2 adsorption and mercury porosimetry analysis.
PY - 2018
Y1 - 2018
N2 - Microbial electrosynthesis (MES) allows recycling of CO into value added products by coupling renewable energy to the microbial ability for complex product formation. To improve biofilm formation on the cathode and the rates of product generation, the design of cathodes possessing a high specific surface area and enhanced electrode-microbe electron transfer is needed. This study aimed to demonstrate a novel cathode design that is made of porous nickel hollow fibers (Ni-PHFs), for facilitating direct delivery of CO to Sporomusa ovata in MES through the pores in the hollow fibers. Modification of the surface of Ni-PHFs with carbon nanotubes (CNTs) resulted in an 11-fold increase in the CO adsorption capability at atmospheric pressure, as well as 76.3% reduction of cathode electron transfer resistance. This cathode surface modification partially explained the higher acetate production rate of 247 ± 17 mM d m from direct CO delivery through the pores of the Ni-PHF/CNT cathode, compared to 145 ± 4 mM d m for the Ni-PHF cathode. Higher electron recovery in the form of acetate (∼83%) was also observed for the Ni-PHF/CNT cathode. As for the tests where CO was sparged into the medium, acetate production was 36% lower than tests with direct CO delivery to S. ovata through the pores of the Ni-PHF/CNT cathode. These results demonstrate that using the PHF electrode design and modifying the cathode morphology to enhance the microbe-electrode interactions and CO availability for bacterial growth are effective approaches to increase the rates of CO reduction in MES.
AB - Microbial electrosynthesis (MES) allows recycling of CO into value added products by coupling renewable energy to the microbial ability for complex product formation. To improve biofilm formation on the cathode and the rates of product generation, the design of cathodes possessing a high specific surface area and enhanced electrode-microbe electron transfer is needed. This study aimed to demonstrate a novel cathode design that is made of porous nickel hollow fibers (Ni-PHFs), for facilitating direct delivery of CO to Sporomusa ovata in MES through the pores in the hollow fibers. Modification of the surface of Ni-PHFs with carbon nanotubes (CNTs) resulted in an 11-fold increase in the CO adsorption capability at atmospheric pressure, as well as 76.3% reduction of cathode electron transfer resistance. This cathode surface modification partially explained the higher acetate production rate of 247 ± 17 mM d m from direct CO delivery through the pores of the Ni-PHF/CNT cathode, compared to 145 ± 4 mM d m for the Ni-PHF cathode. Higher electron recovery in the form of acetate (∼83%) was also observed for the Ni-PHF/CNT cathode. As for the tests where CO was sparged into the medium, acetate production was 36% lower than tests with direct CO delivery to S. ovata through the pores of the Ni-PHF/CNT cathode. These results demonstrate that using the PHF electrode design and modifying the cathode morphology to enhance the microbe-electrode interactions and CO availability for bacterial growth are effective approaches to increase the rates of CO reduction in MES.
UR - http://hdl.handle.net/10754/631290
UR - https://pubs.rsc.org/en/Content/ArticleLanding/2018/TA/C8TA05322G#!divAbstract
UR - http://www.scopus.com/inward/record.url?scp=85053513316&partnerID=8YFLogxK
U2 - 10.1039/c8ta05322g
DO - 10.1039/c8ta05322g
M3 - Article
AN - SCOPUS:85053513316
VL - 6
SP - 17201
EP - 17211
JO - Journal of Materials Chemistry A
JF - Journal of Materials Chemistry A
SN - 2050-7488
IS - 35
ER -
