Microbial electrolysis cells for hydrogen production

Abstract

Microbial electrolysis cells (MECs) present an attractive route for energy-saving hydrogen (H2) production along with treatment of various wastewaters, which can convert organic matter into H2 with the assistance of microbial electrocatalysis. However, the development of such renewable technologies for H2 production still faces considerable challenges regarding how to enhance the H2 production rate and to lower the energy and the system cost. In this review, we will focus on the recent research progress of MEC for H2 production. First, we present a brief introduction of MEC technology and the operating mechanism for H2 production. Then, the electrode materials including some typical electrocatalysts for hydrogen production are summarized and discussed. We also highlight how various substrates used in MEC affect the associated performance of hydrogen generation. Finally we presents several key scientific challenges and our perspectives on how to enhance the electrochemical performance.

Performance efficiency comparison of microbial electrolysis cells for sustainable production of biohydrogen—A comprehensive review

“…Figure 2A represents the H‐shaped double chamber MEC configuration designed and experimented by Liu et al, this was the most common MEC configuration in the beginning and achieved the maximum CE of 78% and HPR of 0.37 m 3 ‐H 2 /m 3 /d. However, this configuration had various energy losses due to many factors, such as Ohmic loss, less membrane area, activation loss, and concentration loss 21,51 . A cubical, double chamber, MEC reactor (Figure 2C) was tested to overcome the previously mentioned problems and achieved 1.1 m 3 ‐H 2 /m 3 /d HPR and 82% energy efficiency at an applied voltage of 0.6 V. This was because of less separation distance between both electrodes due to cubicle configuration 44 .…”

“…The most satisfactory substitutes of platinum for fast HER are transition metal compounds of first row of periodic table because of their moderate catalytic activity, abundance, and stability 58 . The stainless steel and nickel‐based materials, among other materials, are the extensively reported cathode materials till now because these materials have low cost, are plentiful in nature, excellent catalytic action for HER and have stable electrochemical property 39,51 . Jeremiasse et al published a research paper in 2010 utilizing Ni‐foam as cathode in double chamber MEC system.…”

“…Graphite materials have superior stability and electric conductivity compared to the ordinary carbon‐based materials but is more expensive. The graphite fiber brush is considered as the most favorable anode material in future because of its easy availability, low electrical resistance, and high surface area 25,51,71 . Call et al reported the use of brush made of graphite fibers as anode material in single chamber MEC.…”

“…58 The stainless steel and nickelbased materials, among other materials, are the extensively reported cathode materials till now because these materials have low cost, are plentiful in nature, excellent catalytic action for HER and have stable electrochemical property. 39,51 Jeremiasse et al published a research paper in 2010 utilizing Ni-foam as cathode in double chamber MEC system. This system was operated at 0.1 V applied potential and achieved 90% CE and 50 L/L/d of HPR.…”

“…The graphite fiber brush is considered as the most favorable anode material in future because of its easy availability, low electrical resistance, and high surface area. 25,51,71 Call et al reported the use of brush made of graphite fibers as anode material in single chamber MEC. They successfully achieved the maximum HPR of 1.7 ± 0.1 m 3 -H 2 /m 3 /d and 78% CE at 0.6 V applied .…”