Nitrogen-doped activated carbon as a metal free catalyst for hydrogen production in microbial electrolysis cells

Nitrogen-doped activated carbon was investigated as an alternative cathode catalyst for hydrogen production in microbial electrolysis cells (MECs). Both electrochemical and MEC tests confirmed that nitrogen doping was an effective method in improving the catalytic activity of activated carbon towards the hydrogen evolution reaction (HER). This improvement was attributed to the increased nitrogen content in activated carbon, as a higher content of nitrogen would facilitate the Volmer step in HER. Although the overall performance of the nitrogen-doped activated carbon was lower than the platinumbased catalysts, its low cost and (potentially) long-term stability would compensate for a low hydrogen production rate.