Fig. 5: Electrochemical HOR performance.
a HOR polarization curves of different catalysts. b Polarization curves of Ru–Cr1(OH)x−1.1 at different rotation speeds (ω) of 400, 900, 1600, and 2500 rpm (from bottom to top). Inset is the Koutecky–Levich plot at an overpotential of 25 mV. c Calculated HOR kinetic current densities (jk) vs. potential plots recorded from a. d Comparison of jk and j0 of Ru–Cr1(OH)x−0.6 (black), Ru–Cr1(OH)x−1.1 (red), Ru–Cr1(OH)x−2.2 (blue), Ru NPs (green), and Pt/C (pink). Error bars show as mean s.d. e HOR polarization curves for Ru–Cr1(OH)x−1.1 (red), Ru NPs (green) and Pt/C (pink) in H2-saturated 0.1 M KOH without (solid lines) and with (dashed lines) the presence of 20,000 p.p.m. CO. f Relative current-time chronoamperometry of different catalysts at an overpotential of 50 mV operated on RDE. g Relative current-time chronoamperometry response of Ru–Cr1(OH)x−1.1 catalyst loaded on carbon fiber paper at an overpotential of 50 mV in a H-type cell. h HER polarization curves in 0.1 M KOH solution at a rotating speed of 1600 rpm.
