CONSTRUCTION OF MICROBIAL ELECTROLYSIS CELLS, SYNTHESIS AND EXAMINATION OF NOVEL CATALYSTS FOR HYDROGEN PRODUCTION

Bio-hydrogen may play a central role in a future energy economy which will be based on non-fossil fuels. A microbial electrolysis cell (MEC) utilizes a microbial anode and a hydrogen reduction catalyst cathode. The anodic part is based on exo-electrogenic bacteria that maintain an effective electrochemical charge transfer with the anode, while preforming their metabolic process of oxidizing hydrocarbon substrates to electrons and protons. The cathodic reaction of proton reduction to hydrogen has a lower redox potential than the anodic redox bacterial reaction.

In this study, we designed dual chamber MEC systems that consist of bacterial anodes and treated carbon cloth cathodes loaded with novel molybdenum disulfide (MoS₂) catalysts. The power generated in the MEC that was based on G. sulfurreducens provided 30 times more current than MEC which was based on C. basilensis. HPLC analysis rate of phenol degradation showed a phenol degradation of 52 mg/L/day. Particle size measurements showed that the synthesized MoS₂ particles are 10-20 times smaller than commercial MoS₂, and are electrochemically more active in hydrogen generation. A plasma-treated carbon cloth cathode loaded with a MoS₂ catalyst synthesized by BuLi, a polylysine-treated carbon cloth cathode loaded with a MoS₂ catalyst synthesized by BuLi and a pristine carbon cloth cathode loaded with a MoS₂ catalyst synthesized by ball milling exhibited an improvement of 615%, 260% and 160%, respectively, compared to a pristine carbon cloth cathode with a commercial MoS₂ catalyst. The calculated hydrogen production rate was The hydrogen purity, based on gas chromatography analysis, was approximately 100%.

In conclusion, this study demonstrates the possibility of hydrogen generation from harmful wastes such as phenol using select low-cost microbial anodes and treated carbon cloth cathodes coated with novel synthesized MoS₂ catalysts.