A research team, affiliated with UNIST has made a significant breakthrough in sustainable technology with the development of a method to convert carbon dioxide (CO₂) into methanol, a process that could play a crucial role in reducing greenhouse gas emissions and producing eco-friendly fuels.
A team led by Professor Jungki Ryu from the School of Energy and Chemical Engineering at UNIST, in collaboration with Professors Jongsoon Kim of Sungkyunkwan University (SKKU) and Aloysius Son of Yonsei University, announced on the 26th the successful development of a copper-based catalyst capable of transforming CO₂ into high-purity methanol.
Methanol is a versatile chemical used as a fundamental raw material in the production of plastics and synthetic fibers. Its liquid state facilitates easy storage and transportation, making it increasingly attractive as a hydrogen carrier and fuel cell fuel. Producing methanol directly from CO₂ not only helps reduce carbon emissions but also offers a sustainable route for resource utilization. However, traditional conversion processes often result in mixtures containing undesired byproducts like hydrogen and methane, requiring complex purification steps.
The innovative copper catalyst developed by the research team selectively produces methanol with remarkable efficiency. It achieved a maximum selectivity of up to 70%, among the highest reported for copper-based catalysts, rivaling the performance of costly precious metal catalysts. Typical copper catalysts exhibit selectivities of only 10-30%.
This catalyst features a unique, tightly integrated structure where nanoscale copper(I) pyrophosphate (Cu₂P₂O₇) particles are seamlessly combined with pure copper metal, resembling a puzzle fit. This configuration suppresses competing reactions that produce hydrogen, enabling highly selective methanol synthesis.
Remarkably, the team fabricated this complex structure using an innovative approach inspired by lithium-ion battery discharge principles. By passing an electric current through the electrode during battery-like discharge, some copper pyrophosphate is reduced to metallic copper, causing the two materials to naturally form a composite within a single particle. Post-reaction, residual materials can be easily washed away with water, simplifying the process.
Additionally, the study uncovered an alternative reaction pathway for methanol synthesis that departs from conventional mechanisms. Instead of proceeding through carbon monoxide (CO), the catalyst first produces formic acid (HCOOH), which is then converted into methanol-offering new insights that could inform future catalyst development and deepen our understanding of methanol synthesis pathways.
Professor Ryu emphasized, “Methanol is a critical industrial raw material and energy source consumed worldwide in the millions of tons annually. This cost-effective catalyst, made from inexpensive copper, demonstrates high selectivity and current density, bringing us closer to industrial-scale ‘carbon resource conversion’-directly transforming CO₂ into valuable resources.”
He added, “Utilizing principles from battery technology to fabricate the catalyst highlights its potential for practical, large-scale applications. We plan to expand this technology by scaling up electrode areas and integrating systems for commercial deployment.”
This research involved contributions from UNIST School of Energy and Chemical Engineering, including Dr. Hyunwoo Kim and Suhwan Park, as well as Jihoe Lee from SKKU and Sangseob Lee from Yonsei University.
Recognized for its excellence and potential impact, the study was published online on May 20 in the prestigious scientific journal Advanced Materials, supported by the National Research Foundation of Korea (NRF) and the Ministry of Science and ICT (MSIT).