Converting Captured Carbon Dioxide into Cement Precursors

Researchers at the University of Michigan (U-M) have helped develop a new method to turn carbon dioxide into useful materials for cement production.

Carbon dioxide is a common industrial waste and a major atmospheric pollutant. This research offers a way to use captured carbon dioxide to create cement precursors.

In collaboration with Jesús Velázquez’s lab at the University of California, Davis, Anastassia Alexandrova's lab at the University of California, Los Angeles, and U-M chemist Charles McCrory and his team, researchers developed a method to capture carbon dioxide and convert it into metal oxalates. These compounds can then be used as building blocks in cement production.

This research shows how we can take carbon dioxide, which everyone knows is a waste product that is of little-to-zero value, and upcycle it into something that’s valuable. We’re not just taking carbon dioxide and burying it; we’re taking it from different point sources and repurposing it for something useful.

Charles McCrory, Associate Professor, Chemistry and Macromolecular Science and Engineering, University of Michigan

The idea for the study began with McCrory’s work at the Center for Closing the Carbon Cycle (4C). Led by Jenny Yang at the University of California, Irvine, 4C is an Energy Frontier Research Center supported by the U.S. Department of Energy’s Office of Science, Basic Energy Sciences. One of its goals is to find ways to capture and convert carbon dioxide into useful fuels and materials.

Portland cement, the most common type, is typically made from limestone and minerals like calcium silicates. McCrory notes that making Portland cement uses a lot of energy and produces a significant amount of carbon emissions. His team was exploring ways to use carbon dioxide to create ingredients for alternative types of cement.

Metal oxalates, a type of simple salt, can be used as an alternative cement precursor. Researchers found that lead can act as a catalyst to convert carbon dioxide into metal oxalates. However, the original method required large amounts of lead, which is harmful to both people and the environment.

To solve this, the 4C team used polymers to control the area around the lead catalyst. This approach reduced the amount of lead needed to just parts per billion, similar to levels found in many commercial graphite and carbon products.

McCrory’s work focuses on controlling the "microenvironment," which refers to the chemical surroundings of catalyst sites. By adjusting this microenvironment, he can influence how the catalyst behaves.

The team showed that by managing the microenvironment around the lead catalyst, they could greatly reduce the amount of lead needed to turn CO₂ into oxalate.

To produce oxalate from CO₂, the researchers used a system with two electrodes. At one electrode, CO₂ is converted into oxalate, a dissolved ion. At the other, a metal electrode releases metal ions that bind with the oxalate, forming a solid metal oxalate that can be collected.

“Those metal ions are combining with the oxalate to make a solid, and that solid crashes out of the solution. That’s the product that we collect and that can be mixed in as part of the cement-making process,” added McCrory.

Velázquez, a co-lead author of the study and an associate professor of chemistry at UC Davis, helped develop the idea of using small amounts of lead to drive the conversion of carbon dioxide into oxalate. His team also studied how the chemical reaction works.

Metal oxalates represent an underexplored frontier—serving as alternative cementitious materials, synthesis precursors, and even carbon dioxide storage solutions.

Jesús Velázquez, Study Co-Lead Author and Associate Professor, Chemistry, University of Michigan

Alexandrova, also a co-lead author and a professor of chemistry and materials science at UCLA, led the team that ran calculations to support the idea and confirm that the process could work.

Catalysts are often discovered by accident, and successful industrial formulations are often very complicated. These cocktail catalysts are discovered empirically through trial and error. In this work, we have an example of a trace lead impurity actually being a catalyst. I believe there are many more such examples in practice catalysis, and also that this is an underexplored opportunity for catalyst discovery.

Anastassia N. Alexandrova, Professor, University of Michigan

According to McCrory, once carbon dioxide is turned into a solid metal oxalate, it cannot easily return to the atmosphere as carbon dioxide under normal conditions.

“It’s a true capture process because you’re making a solid from it. But it’s also a useful capture process because you’re making a useful and valuable material that has downstream applications,” stated McCrory.

He believes that one part of the process—using electrolysis to convert carbon dioxide—can be scaled up. The next step is to explore how to scale the part of the process that produces the solid material.

“We are a ways away, but I think it’s a scalable process. Part of the reason we wanted to reduce the lead catalyst to parts per billion is the challenges of scaling up a catalyst with massive amounts of lead. It wouldn’t be environmentally reasonable, otherwise,” concluded McCrory.

Journal Reference:

Brower, R. S., et al. (2025). Selective Electrochemical Reduction of CO₂ to Metal Oxalates in Nonaqueous Solutions Using Trace Metal Pb on Carbon Supports Enhanced by a Tailored Microenvironment. Advanced Energy materials. doi.org/10.1002/aenm.202501286