Asymmetric Neutral‐alkaline Microbial Electrolysis Cells for Hydrogen Production

The development of highly efficient cathodes for hydrogen production that can operate in a suitable pH condition is a daunting challenge in microbial electrolysis cells (MECs). Herein, an asymmetric neutral-alkaline double-chamber microbial electrolysis cells (AMECs) by using conventional carbon brush with microorganism attached as neutral anode and the Ru/CNTs electrode as alkaline cathode, respectively, was proposed. To implement this, a hybrid with ruthenium nanoparticles loaded on conductive carbon nanotubes (Ru/CNTs) was prepared by a reduction deposition method, which exhibited comparable electrocatalytic performance to the expensive benchmark Pt/C catalysts for hydrogen evolution reaction (HER). Compared to the traditional MECs running in symmetric neutral electrolyte, the as-developed AMEC displayed a higher current density of 17.13 A m(-2) and hydrogen production rate of 0.167 m(3) m(-2) d(-1). The present AMEC provides an energy-saving and cost-effective process technology for electrolysis H-2 generation.