Enhancement of hydrogen production in a single chamber microbial electrolysis cell through anode arrangement optimization

► The optimization of anode arrangement is effective to reduce the inner resistance of microbial electrolysis cells (MECs). ► Separately placing the anodes on both sides of the cathode improved the current and hydrogen production rate of MECs. ► A maximum current density of 1355 A/m3 with a high hydrogen production rate of 10.88 m3/m3 d can be achieved. ► Modifying the anode into stacking mode made the polarization and biofilm resistance of MEC decreased by 35% and 78%.