Developing sustainable and energy‐efficient methods for hydrogen production is vital for advancing clean energy technologies. One of the major challenges in water electrolysis is the high overpotential and sluggish kinetics of the oxygen evolution reaction (OER), which significantly limits overall efficiency. This study explores the use of alternative oxidation reactions—specifically, the hydrogen peroxide oxidation reaction (HPOR) and methanol oxidation reaction (MOR)—as promising substitutes to overcome the limitations of OER. Electrochemical investigations revealed that the catalyst exhibited a high Tafel slope of 126.0 mV/dec and an onset potential of 1.60 V versus RHE for OER. The highest current density of 0.93 mA/cm 2 is obtained at a potential of 1.67 V versus RHE, underscoring the slow reaction kinetics of OER. By comparison, MOR achieved an onset potential as low as 1.46 V versus RHE at a methanol concentration of 1.17 M, bringing a maximum current density of 8.21 mA/cm 2 —nearly nine times higher than OER—with a lowered Tafel slope of 75.0 mV/dec. Importantly, MOR required 180 mV less potential to accomplish the similar current density (0.93 mA/cm 2 ) as OER. HPOR showed even greater promise, initiating oxidation at an onset potential of just 0.97 V versus RHE and attaining a maximum current density of 10.13 mA/cm 2 at 1.37 V versus RHE. The potential required for HPOR to reach the same current density as OER was reduced by 650 mV, and its Tafel slope fall further to 55.9 mV/dec at a H 2 O 2 concentration of 0.46 M, indicating highly favorable reaction kinetics. Stability tests confirmed that the catalyst maintained robust performance for both MOR and HPOR over extended periods. Nevertheless, the findings highlight that both MOR and HPOR are promising pathways to improve the efficiency of hydrogen production by providing viable, lower‐potential alternatives to the conventional OER.
Ullah et al. (Tue,) studied this question.