Researchers have developed a low-lead process to convert carbon dioxide, a major industrial pollutant, into solid metal oxalates that can be used as precursors for cement production.

At the University of Michigan, chemist Charles McCrory and his team, collaborating with labs at the University of California, Davis, and UCLA, created a method to capture carbon dioxide and transform it into valuable metal oxalates. These compounds serve as essential building blocks for cement manufacturing.

Figure 1. New Method Turns CO₂ Into Sustainable Cement Material

“This research demonstrates how carbon dioxide, typically seen as a worthless waste product, can be upcycled into a valuable resource,” said McCrory, associate professor of chemistry and macromolecular science and engineering. “Instead of simply burying carbon dioxide, we are repurposing it from various sources into something useful.” Figure 1 shows New Method Turns CO₂ Into Sustainable Cement Material.

This research was driven by McCrory’s involvement in the Center for Closing the Carbon Cycle (4C), an Energy Frontier Research Center funded by the U.S. Department of Energy’s Office of Science, Basic Energy Sciences. Led by Jenny Yang at the University of California, Irvine, 4C aims to develop innovative methods for capturing and converting carbon dioxide into useful fuels and valuable products.

A Greener Substitute for Conventional Cement

Portland cement, the most widely used type, is typically made from limestone and calcium silicates, but its production carries a high energy cost and significant carbon footprint. Seeking cleaner alternatives, McCrory and his team explored converting carbon dioxide into materials that could serve as alternative cement precursors.

One such material is metal oxalates—simple salts that can be produced from CO₂ using lead as a catalyst. However, traditional methods require large amounts of lead, posing serious environmental and health risks.

To solve this, the 4C team developed a way to use polymers to precisely control the chemical environment around the lead catalysts. This innovation reduced the lead needed for the reaction to trace amounts—just parts per billion, levels already found in many commercial carbon materials.

McCrory, who specializes in tuning catalyst microenvironments, explained that adjusting the surroundings of the lead catalyst allowed the team to dramatically cut down the amount of lead required while still effectively converting CO₂ into oxalates.

Electrochemical Method for Carbon Conversion

To convert carbon dioxide into metal oxalates, researchers used a specialized electrochemical process involving two electrodes. At one electrode, CO₂ is transformed into oxalate ions dissolved in the solution. Simultaneously, the metal electrode at the other end oxidizes, releasing metal ions that bind with the oxalate to form solid metal oxalates, which then precipitate out of the solution.

“These metal ions combine with the oxalate to form a solid that crashes out of solution,” explained McCrory. “We collect that solid, which can then be incorporated into the cement-making process.”

Co-lead author Jesús Velázquez, associate professor of chemistry at UC Davis, first proposed using trace amounts of lead to drive the oxalate-synthesis reaction and investigated the underlying chemical mechanisms. “Metal oxalates are an underexplored area,” he said, “offering potential as alternative cement materials, chemical precursors, and even carbon storage solutions.”

Anastassia Alexandrova, co-lead author and professor of chemistry and materials science at UCLA, led the computational modeling that confirmed the feasibility of the process. “Catalysts are often discovered by chance, and many effective industrial catalysts are complex mixtures found through trial and error,” she said. “In this case, a trace amount of lead acted as a catalyst. I believe there are many more such overlooked catalysts waiting to be discovered.”

Practical CO₂ Capture With Real-World Impact

McCrory explains that once carbon dioxide is converted into a solid metal oxalate, it remains stable and won’t revert to CO₂ under normal conditions.

“This is genuine carbon capture,” he said. “We’re not just locking away CO₂—we’re turning it into a solid that’s both stable and useful, with real downstream applications.”

He noted that part of the process—electrolysis of carbon dioxide—is already being explored at scale, and the next challenge is scaling up the solid product formation. “We’re still some distance from full-scale application, but it’s a process with real potential,” McCrory said [1]. “One reason we focused on reducing the lead catalyst to parts per billion was to ensure the process remains environmentally viable during scale-up. Using large amounts of lead simply wouldn’t be practical or safe.”

References:

1. https://scitechdaily.com/researchers-transform-carbon-waste-into-valuable-building-material/

Cite this article:

Janani R (2025), Researchers Turn Carbon Waste Into High-Value Construction Material, AnaTechMaz, pp. 241