Microbial Electrocatalysis for Efficient Medium-Chain Carboxylic Acid (MCCA) Synthesis from Captured CO2

• Grant number: 24/16844-8
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: March 01, 2026
• End date: February 28, 2029
• Field of knowledge: Interdisciplinary Subjects
• Principal Investigator: Pablo Sebastián Fernández
• Grantee: Benjamin Nahuel Viada
• Host Institution: Instituto de Química (IQ). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Company: Universidade Estadual de Campinas (UNICAMP). Instituto de Química (IQ)
• Associated research grant: 17/11986-5 - Generation and storage of New Energy: bringing technological development for the country, AP.PCPE

Abstract

CO2 is one of the main contributors to global warming, and its emissions must be reduced to mitigate rising sea levels, extreme weather events, and ecosystem disruptions. Carbon capture technologies can help remove CO2 from the atmosphere. Bioenergy, in turn, is a clean and renewable energy source. Brazil, for example, is a global leader in sugarcane ethanol production. While this process does emit CO2, its carbon-neutral nature and potential for carbon capture make it a sustainable alternative to fossil fuels. Microbial electrosynthesis (MES) presents a promising technology for bio-electrochemical conversion of released CO2 into valuable chemicals. This technology combines the advantages of electrochemistry and biotechnology to produce chemicals like medium-chain carboxylic acids (MCCAs). Butyric (four carbons, C4) and caproic (six carbons, C6) acids, in particular, find widespread applications in various industries, including pharmaceuticals, fragrances, rubbers, and renewable fuels, among others. Despite the promising potential of microbial CO2 reduction for producing MCCAs, current research indicates that production rates are lower than those achieved in alternative fermentation technologies, such as syngas fermentation and chain elongation fermentation. To significantly enhance the performance and efficiency of MES systems, we must first delve into the underlying factors that govern bioelectrochemical activity (as measured by current) and product selectivity. A deep understanding of these mechanisms will enable us to optimize system parameters rationally. Firstly, the selection of electroactive microbial communities is crucial. These microorganisms play a vital role in converting CO2 into valuable products. Secondly, the dynamics of biofilm formation and characteristics at the cathodes that are essential for efficient electron transfer and CO2 reduction should be studied. Thirdly, optimizing operational parameters such as pH, temperature, and applied potential can significantly impact the productivity and selectivity of the MES system. This research focuses on developing a comprehensive MES system that harnesses the potential of CO2 to produce carbon-based chemicals sustainably. By optimizing MES systems in terms of cathode performance, microbial community, and long-term stability, we aim to develop a more promising system for both carbon-based chemical production and CO2 sequestration. (AU)