Role of microbial electrosynthesis system in CO2 capture and conversion: a recent advancement toward cathode development

Abstract

Microbial electrosynthesis (MES) is an emerging electrochemical technology currently being researched as a CO2 sequestration method to address climate change. MES can convert CO2 from pollution or waste materials into various carbon compounds with low energy requirements using electrogenic microbes as biocatalysts. However, the critical component in this technology, the cathode, still needs to perform more effectively than other conventional CO2 reduction methods because of poor selectivity, complex metabolism pathways of microbes, and high material cost. These characteristics lead to the weak interactions of microbes and cathode electrocatalytic activities. These approaches range from cathode modification using conventional engineering approaches to new fabrication methods. Aside from cathode development, the operating procedure also plays a critical function and strategy to optimize electrosynthesis production in reducing operating costs, such as hybridization and integration of MES. If this technology could be realized, it would offer a new way to utilize excess CO2 from industries and generate profitable commodities in the future to replace fossil fuel-derived products. In recent years, several potential approaches have been tested and studied to boost the capabilities of CO2-reducing bio-cathodes regarding surface morphology, current density, and biocompatibility, which would be further elaborated. This compilation aims to showcase that the achievements of MES have significantly improved and the future direction this is going with some recommendations.Highlights– MES approach in carbon sequestration using the biotic component.– The role of microbes as biocatalysts in MES and their metabolic pathways are discussed.– Methods and materials used to modify biocathode for enhancing CO2 reduction are presented.

Progress and Prospects for Applications of Extracellular Electron Transport Mechanism in Environmental Biotechnology

“…The standardization of testing methods to analyze the performance is anticipated in future studies, which is essential for advancing BES and EET technology and further scale-up. 102 It is considered a potentially sustainable process for transforming electrical energy (produced by renewable sources) into easily storable chemicals under mild environments. 103 In MES, the electroactive microorganisms (called electrotrophs) can utilize electrons (e − ) from external conductors (electrode) as the reducing power for CO 2 conversion.…”

“…MES is an emerging bioelectrochemical technology for CO 2 sequestration to address climate change . It is considered a potentially sustainable process for transforming electrical energy (produced by renewable sources) into easily storable chemicals under mild environments .…”