Current Happenings ENVS News

  • Introducing perovskite-based catalyst for microbial fuel cell April 8, 2022

    MFC

    Microbial fuel cells (MFCs) are biochemical systems producing green energy through the microbial degradation of organic contaminants in wastewater. The Oxygen Reduction Reaction (ORR) that takes place at MFC cathode decides the overall output of energy generation. Hence, the selection of ORR catalyst becomes pivotal in MFC fabrication for its efficiency and cost effectiveness. Gopa Nandikes P, PhD Scholar, Department of Environmental Science, proposes perovskite-based nanocatalyst as an excellent replacement to Platinum in his paper “Perovskite-Based Nanocomposite Electrocatalysts: An alternative to Platinum ORR Catalyst in Microbial Fuel Cell Cathodes”. The paper is published in ‘Energies Journal’ having an Impact Factor of 3.04.

    The paper comprehensively summarises all the studies conducted with perovskite-based ORR catalyst in MFC, its unique reaction mechanism and the synergistic effect with carbon. The paper also throws light into various challenges and prospects to further improve the ORR activity of perovskite-based catalysts.

    Abstract of the Research

    ORR Mechanism

    Microbial fuel cells (MFCs) are biochemical systems having the benefit of producing green energy through the microbial degradation of organic contaminants in wastewater. The efficiency of MFCs largely depends on the cathode oxygen reduction reaction (ORR). A preferable ORR catalyst must have good oxygen reduction kinetics, high conductivity, and durability, together with cost-effectiveness. Platinum-based electrodes are considered a state-of-the-art ORR catalyst. However, the scarcity and higher cost of Pt are the main challenges for the commercialization of MFCs; therefore, in search of an alternative, cost- effective catalysts, those such as doped carbons and transition-metal based electrocatalysts have been researched for more than a decade. Recently, perovskite-oxide based nanocomposites have emerged as a potential ORR catalyst due to their versatile elemental composition, molecular mechanism, and the scope of nanoengineering for further developments. In this article, we discuss various studies conducted and opportunities associated with perovskite-based catalysts for ORR in MFCs. Special focus is given to a basic understanding of the ORR reaction mechanism through oxygen vacancy, modification of its microstructure by introducing alkaline earth metals, electron transfer pathways and the synergistic effect of perovskite and carbon. At the end, we also propose various challenges and prospects to further improve the ORR activity of perovskite-based catalysts.

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  • Innovatory conversion of bagasse to biogas March 15, 2022

    The Department of Environmental Science is glad to announce that Dr Lakhveer Singh has published a paper titled “Anaerobic digestion of sugarcane bagasse for biogas production and digestate valorization” in the journal ‘Chemosphere’ having an impact factor of 7.08 in collaboration with IIT Delhi.

    Abstract of the Research

    The complex structure of biomass is recalcitrant to degradation and is a major hindrance for anaerobic digestion, so different pre-treatment methods are applied to deconstruct the bagasse for microbial digestion. In this review, different processes developed for the pre-treatment of bagasse and their effect on biogas production have been extensively covered. Moreover, combinations of pre-treatment methods, co-digestion of bagasse with other waste (nitrogen-rich or easily digestible) for enhanced biogas production and biomethane generation along with other value-added products have also been reviewed. Thus, this review highlights the major emerging area of research for improvement in bagasse-based processes for enhanced biogas production along with digestate valorization to make the overall process economical and sustainable.

    The paper offers a promising solution with respect to the conversion of agricultural waste to biomethane along with other value-added products. As far as Dr Singh is concerned, future research should also be directed towards the life cycle assessment of different integrated technologies for quantifying the environmental and economic benefits which will help to choose the most sustainable option for digestate valorization.

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