Breakthrough Method Converts Carbon Dioxide into Sustainable Liquid Fuel
December 19, 2024 | By Dave DeFusco
A team of scientists has developed a new way to turn carbon dioxide into methanol, a valuable liquid fuel with high energy density and versatility. The study, “Room-Temperature Formate Ester Transfer Hydrogenation Enables an Electrochemical/Thermal Organometallic Cascade for Methanol Synthesis from CO2,” published in Angewandte Chemie, not only advances understanding of catalysis but also paves the way for renewable energy conversion and CO2, or carbon dioxide, valorization.
The research team, which is part of the Department of Energy’s Center for Hybrid Approaches in Solar Energy to Liquid Fuels (CHASE), introduces a novel multi-catalyst system that operates at room temperature and normal atmospheric pressure—conditions critical for integration with electric power obtained from renewable energy sources, such as solar and wind.
Methanol has long been viewed as a key player in the push toward sustainable energy, with fuel applications ranging from IndyCar racing to maritime shipping. Compatibility with combustion engines and fuel cells makes methanol a promising option for reducing reliance on fossil fuels; however, producing methanol from carbon dioxide is a long-standing challenge. Conventional methods rely on high temperatures, high pressures and hydrogen derived from fossil fuels—factors that make them less sustainable and hard to integrate with renewable energy.
“Our study tackles this challenge head-on, offering a method to synthesize methanol under conditions that could be coupled with renewable electricity,” said Dr. Sergio Fernández, one of the authors of the study and a postdoctoral researcher in the Miller Group at UNC-Chapel Hill’s Department of Chemistry. “This is a significant step forward in developing innovative strategies to transform CO2, a major greenhouse gas, into sustainable liquid fuels.”
The research team, which also included scientists from CHASE investigators at Yale University and Brookhaven National Laboratory, also found that isopropanol plays a crucial role beyond acting as a solvent. It participates in the reactions by donating hydrogen and helps lower energy barriers through hydrogen bonding. This dual functionality makes the process feasible under mild reaction conditions.
“The impact of this research extends beyond energy storage. Methanol is not just a fuel; it’s also a building block for producing a wide range of chemicals and materials,” said Dr. Fernández.
Moreover, the study demonstrates how to integrate two traditionally separate fields: electrochemical and thermal catalysis. By harmonizing these methods, the team has set the stage for future innovations in “cascade catalysis,” where multiple steps work seamlessly together to achieve complex chemical transformations.
“This study is exciting because it helps us build a framework for understanding how electrochemical and thermal catalytic reactions can be integrated,” said Dr. Alexander Miller, a lead author on the study and professor of chemistry at UNC-Chapel Hill. “The approach of pairing different modes of catalysis could also be beneficial to other chemical transformations beyond methanol production.”
While the method is an exciting advance, some challenges remain. For example, the esterification step—the conversion of formate into an ester, a type of chemical compound that is typically formed when an acid reacts with an alcohol—was one of the more difficult parts of the process. The researchers identified this as the key step in need of further optimization.
“This discovery represents a paradigm shift in how we think about reducing carbon dioxide and producing methanol,” said Dr. Fernández. “Understanding how multiple catalysts cooperate inside the electrochemical cell could unlock unexplored reaction pathways, revolutionizing the production of chemicals and materials.”