Highly active Pt/NF electrode preparation towards efficient hydrogen production in anaerobic fermentation liquid

Hydrogen, recognized for its high energy density and zero carbon emissions, faces challenges in resource-efficient production. Meanwhile, anaerobic digestion (AD) is frequently impaired by acidification resulting from the accumulation of volatile fatty acids (VFAs), undermining system stability. Herein, we designed a Pt/NF electrode and utilized VFAs-rich acidogenic fermentation liquid as the feedstock for efficient hydrogen production. The electrochemically deposited Pt/NF electrode exhibited excellent hydrogen evolution reaction (HER) activity (overpotential of 340.63 mV at 10 mA/cm²) with high stability. The hydrogen yield of the Pt/NF system was strongly influenced by the applied voltage as well as the type and concentration of VFAs, peaking at 976.20 mL/g CH₃COOH under conditions of 3.00 V using acetic acid at 5.00 g COD/L. Electrolysis of the actual fermentation liquid produced 28.67 mL of hydrogen and achieved Faradaic and energy efficiencies of 93.92% and 34.77%, respectively, accompanied by an increase in pH and retention of VFAs. hese results demonstrate that the Pt/NF system can be effectively integrated with AD to simultaneously produce green hydrogen and regulate acidification, significantly improving the overall AD process performance and stability.