A team of chemists from the University of Michigan, University of California, Davis, and University of California, Los Angeles has developed a novel method to capture carbon dioxide and convert it into metal oxalates—solid compounds that can serve as precursors for cement production. This breakthrough offers a promising route to reduce industrial carbon emissions and repurpose CO₂ into valuable materials.
Led by Charles McCrory, associate professor of chemistry and macromolecular science and engineering at the University of Michigan, the research is part of the Center for Closing the Carbon Cycle (4C), an Energy Frontier Research Center. The 4C initiative, directed by Jenny Yang at UC Irvine, focuses on developing methods to transform captured carbon dioxide into usable fuels and products.
Traditional Portland cement production relies heavily on limestone and other minerals, and the process is energy-intensive with a significant carbon footprint. To create an alternative, McCrory and his collaborators explored the conversion of CO₂ into metal oxalates, which are simple salts that can serve as cementitious materials.
While lead has been previously known to act as a catalyst for converting CO₂ into oxalates, the conventional process requires large amounts of the toxic metal, raising environmental and health concerns. The research team addressed this issue by designing a polymer-based method that precisely controls the chemical environment around the lead catalyst. This allowed them to reduce the required lead to parts-per-billion levels—comparable to the trace amounts found in commercial graphite and carbon materials.
McCrory’s expertise lies in controlling the microenvironment around catalyst sites to improve performance and efficiency. By tuning this environment, the team dramatically enhanced the catalytic activity of trace lead impurities, making the process cleaner and more sustainable.
The process works through an electrochemical reaction involving two electrodes. At one electrode, CO₂ is converted into oxalate ions, which dissolve in solution. At the other, a metal electrode releases metal ions that bind with the oxalate ions, forming solid metal oxalates that precipitate out of the solution. These solids can be collected and used directly in cement manufacturing.
Jesús Velázquez, associate professor of chemistry at UC Davis and co-lead author of the study, contributed the concept of using trace lead as a catalyst and investigated the underlying reaction mechanisms. He highlighted the broader potential of metal oxalates, not only as cement precursors but also for CO₂ storage and material synthesis.
Anastassia Alexandrova, professor of chemistry and materials science at UCLA and also a co-lead author, led computational studies that confirmed the viability of the proposed reaction. Her team emphasized the underappreciated role of trace impurities in catalysis, pointing to new opportunities for discovering effective catalysts in seemingly ordinary materials.
One key advantage of this approach is the stability of the final product. Once CO₂ is converted into solid metal oxalates, it remains locked in a stable form, preventing its release back into the atmosphere under normal conditions.
Looking ahead, McCrory noted that while the electrochemical conversion of CO₂ is already being developed at scale, efforts are now focused on scaling the production of the solid metal oxalate products. Reducing the lead requirement to trace levels was a critical step in making this process environmentally viable at industrial levels.
Though still in early stages, the method holds promise for creating a scalable, low-impact solution to industrial CO₂ emissions—transforming a major environmental challenge into a useful material for the future of sustainable construction.
By Impact Lab
