Carbon/iron-based nanorod catalysts for hydrogen production in microbial electrolysis cells

Hydrogen production in microbial electrolysis cells (MECs) is a promising approach for harvesting valuable energy products from organic wastes. Catalysts for proton reduction play a central role in decreasing energy input and increasing hydrogen production rates. Here, a novel nitrogen-containing core-shell-structured catalyst N-Fe/Fe ₃C@C was prepared and used to modify cathode electrodes in an MEC. The new catalyst consists of iron-based composite (Fe/Fe ₃C) nanorods as the core and graphite carbon as the shell. The performance of hydrogen production and catalyst stability were investigated. The new catalyst significantly improved hydrogen production compared with unmodified cathode and carbon nanotubes. Although not as efficient as platinum catalysts, a great advantage of the N-Fe/Fe ₃C@C is its extremely low cost (less than 5% of the Pt/C catalyst), suggesting its promise for large-scale MEC applications.