[NiFe]Hydrogenase from Citrobacter sp. S-77 Surpasses Platinum as an Electrode for H sub(2) Oxidation Reaction

Reported herein is an electrode for dihydrogen (H sub(2)) oxidation, and it is based on [NiFe]Hydrogenase from Citrobacter sp. S-77 ([NiFe] sub(S77)). It has a 637 times higher mass activity than Pt (calculated based on 1mg of [NiFe] sub(S77) or Pt) at 50mV in a hydrogen half-cell. The [NiFe] sub(S77) electrode is also stable in air and, unlike Pt, can be recovered 100% after poisoning by carbon monoxide. Following characterization of the [NiFe] sub(S77) electrode, a fuel cell comprising a [NiFe] sub(S77) anode and Pt cathode was constructed and shown to have a a higher power density than that achievable by Pt. Outperforming Pt: An electrode for the H sub(2) oxidation reaction is based on [NiFe]Hydrogenase from Citrobacter sp. S-77 ([NiFe] sub(S77)). It has a 637 times higher mass activity than Pt at 50mV in a hydrogen half-cell, is stable in air and, unlike Pt, can be recovered 100% after poisoning by CO. A fuel cell comprising a [NiFe] sub(S77) anode and Pt cathode was constructed and thus demonstrated a higher power density than that of Pt.