of precious metals from wastes: an answer to manufacturing of cheap nanocatalysts for fuel cells and power generation via an integrated biorefinery?. Biotechnology Letters, Springer Verlag, 2010, 32 (12)
Purpose of workWe have examined the feasibility of using palladium, being recovered microbiologically from industrial processing waste, for the manufacture of a bio-fuel cell for power production.
AbstractBio-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 2 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.