Table 1.

H2 threshold concentrations, ΔG0′ values, and redox potentials of different redox couples with H2 as the electron donor

TEAPH2 threshold concnΔG0′ (kJ/mol of H2)aE0′ (V)bReference(s)
ppmvnM
Acetogenesis430–4,660336–3,640−26.1−0.282, 9
Methanogenesis6–1205–95−33.9−0.248, 9, 32, 33
Sulfate reduction (SO42−→HS)1.3–191–15−38.0−0.228, 9, 33
Fumarate reduction 0.02 0.015−86.2+0.0329
Ammonification (NO3→NH4+)0.02–0.030.015–0.025−149.9+0.368, 9
Nitrate reduction (NO3→N2O, N2)<0.06<0.05 −240+0.7933, 34
Fe(III) reduction0.13–10.1–0.8−228.3+0.778, 33, 34
Chlororespiration<0.4c<0.3c−130 to −1870.30 to 0.55This study
  • a The ΔG0′values were obtained from references 13 through15 and 45 or were calculated from free energies of formation.

  • b The redox potentials (E0′) were calculated by using the relationship E0′ = (ΔG0′/−0.193) − 414 (14, 15, 47).

  • c Data from this study.