Biorefining of precious metals from wastes: an answer to manufacturing of cheap nanocatalysts for fuel cells and power generation via an integrated biorefinery?
Bio-manufacturing of nano-scale palladium was achieved via enzymatically-mediated deposition of Pd from solution using Desulfovibrio desulfuricans, Escherichia coli and Cupriavidus metallidurans. Dried 'Bio-Pd' materials were sintered, applied onto carbon papers and tested as anodes in a proton exchange membrane (PEM) fuel cell for power production. At a Pd(0) loading of 25% by mass the fuel cell power using Bio-Pd( D. desulfuricans ) (positive control) and Bio-Pd( E. coli ) (negative control) was ~140 and ~30 mW respectively. Bio-Pd( C. metallidurans ) was intermediate between these with a power output of ~60 mW. An engineered strain of E. coli (IC007) was previously reported to give a Bio-Pd that was >3-fold more active than Bio-Pd of the parent E. coli MC4100 (i.e. a power output of >110 mW). Using this strain, a mixed metallic catalyst was manufactured from an industrial processing waste. This 'Bio-precious metal' ('Bio-PM') gave ~68% of the power output as commercial Pd(0) and ~50% of that of Bio-Pd( D. desulfuricans ) when used as fuel cell anodic material. The results are discussed in relation to integrated bioprocessing for clean energy.
Yong
Ping
P
Unit of Functional Bionanomaterials, School of Biosciences, The University of Birmingham, Birmingham, B15 2TT, UK.
Mikheenko
Iryna P
IP
Deplanche
Kevin
K
Redwood
Mark D
MD
Macaskie
Lynne E
LE
D001674:Bioelectric Energy Sources; D049921:Cupriavidus / Q000378:metabolism*; D045285:Desulfovibrio desulfuricans / Q000378:metabolism*; D004560:Electricity; D004566:Electrodes / Q000382:microbiology; D004926:Escherichia coli / Q000378:metabolism*; D007220:Industrial Waste; D010165:Palladium / Q000378:metabolism*
D007220:Industrial Waste; D010165:Palladium