A gas breathing hydrogen/air biofuel cell comprising a redox polymer/hydrogenase-based bioanode

Abstract

Hydrogen is one of the most promising alternatives for fossil fuels. However, the power output of hydrogen/oxygen fuel cells is often restricted by mass transport limitations of the substrate. Here, we present a dual-gas breathing H2/air biofuel cell that overcomes these limitations. The cell is equipped with a hydrogen-oxidizing redox polymer/hydrogenase gas-breathing bioanode and an oxygen-reducing bilirubin oxidase gas-breathing biocathode (operated in a direct electron transfer regime). The bioanode consists of a two layer system with a redox polymer-based adhesion layer and an active, redox polymer/hydrogenase top layer. The redox polymers protect the biocatalyst from high potentials and oxygen damage. The bioanodes show remarkable current densities of up to 8 mA cm-2. A maximum power density of 3.6 mW cm-2 at 0.7 V and an open circuit voltage of up to 1.13 V were achieved in biofuel cell tests, representing outstanding values for a device that is based on a redox polymer-based hydrogenase bioanode.

Mechanism and Application of the Catalytic Reaction of [NiFe] Hydrogenase: Recent Developments

“…The redox polymers protected the biocatalyst from high potentials and O 2 damage, and the bioanodes showed remarkable current densities of up to 8 mA/cm 2 . A maximum power density of 3.6 mW/cm 2 at 0.7 V and an open circuit voltage of up to 1.13 V were achieved in biofuel cell tests, representing outstanding values for a device that is based on a redox polymer‐based Dv MF [NiFe] H 2 ase bioanode . The proposed gas‐diffusion redox polymer bioanodes introduce a new concept for the fabrication of highly efficient and protected bioanodes.…”

“…The bioanode consisted of a two layer system with a redox polymer‐based adhesion layer and an active redox polymer/H 2 ase top layer. The redox polymers protected the biocatalyst from high potentials and O 2 damage, and the bioanodes showed remarkable current densities of up to 8 mA/cm 2 . A maximum power density of 3.6 mW/cm 2 at 0.7 V and an open circuit voltage of up to 1.13 V were achieved in biofuel cell tests, representing outstanding values for a device that is based on a redox polymer‐based Dv MF [NiFe] H 2 ase bioanode .…”

“…Szczesny et al. presented a dual‐gas breathing H 2 /O 2 biofuel cell that overcomes these limitations (Figure ) . The biofuel cell was equipped with a H 2 ‐oxidizing redox polymer/ Dv MF [NiFe] H 2 ase gas‐breathing bioanode and an O 2 ‐reducing bilirubin oxidase gas‐breathing biocathode (operated in a direct electron transfer regime).…”

O2 sensitivity and H2 production activity of hydrogenases—A review

“…The authors successfully generated a catalytic current of 200 and −100 mA/cm 3 wherein viologen polymer was used to reactivate the hydrogenase during usage. In another study, Szczesny et al () employed the same enzyme in the H 2 /air biofuel cell and achieved the current density of 8 mA/cm 2 . The use of modified viologen polymer protected the hydrogenase from oxygenic damage.…”

“…Biological production processes are mostly based on the enzyme called hydrogenase, which catalyzes the H 2 oxidation or production reaction (Ergal et al, 2018;Sun, Hopkins, Jenney, McTernan, & Adams, 2010). Attempts have already been made where hydrogenases are used in fuel cells to replace standard noble metal catalysts, or in light-driven photosynthetic systems to convert solar energy into H 2 using water (Noone et al, 2017;Szczesny et al, 2018;Wegelius et al, 2018).…”