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Researchers at Texas A&M University have uncovered how to more efficiently convert carbon dioxide (CO₂) into useful fuels and chemicals, offering a potential boost to both environmental sustainability and local economies.

Led by Dr. Manish Shetty, assistant professor in the Artie McFerrin Department of Chemical Engineering, the study, in the journal Chem Catalysis, explores how certain metals interact with a material called SAPO-34.

"This work is about understanding how to control what we make from CO₂," said Shetty. "If we want to create fuels and chemicals from CO₂, we can. But we need to know how to mix the ingredients in the right way."

A circular economy

Rather than focusing solely on emissions, Shetty's work emphasizes the idea of circularity, reusing carbon as a resource.

"We're not just thinking about CO₂ as a greenhouse gas," he said. "We're asking, can we build a circular economy where carbon is reused instead of wasted?"

The implications extend beyond environmental benefits. By enabling selective production of fuels or chemicals, this research could help industries reduce costs, improve efficiency and adapt to changing market demands.

"If someone comes to us five or 10 years from now and says, 'I want to make propane from CO₂ and hydrogen,' we want to be able to say, 'Pick this metal, pair it with this catalyst, and here's how to put them together,'" he said. "It's like a toolkit for designing the chemical industry of the future."

That future could include not just large-scale refineries, but also smaller, decentralized systems that benefit rural communities.

"For example, the paper and pulp industry or ethanol refineries often emit high-purity CO₂," Shetty explained. "Right now, that CO₂ is just released. But what if we could use it to make propane for local heating or cooking? That's a way to turn waste into value and support local economies."

The perfect recipe

Traditionally, chemical engineers say that bringing different catalyst components closer together improves efficiency. But the team's study challenges that assumption.

"Historically, the idea was that the closer you bring two components, the better the reaction," Shetty said. "But we're finding that's not always true. Sometimes, being too close lets the metal interfere in ways that hurt performance."

The process involves two main steps: first, converting CO₂ and hydrogen into methanol using metal oxides like indium oxide, zinc-zirconium oxide or chromium oxide. Then, methanol is transformed into hydrocarbons using SAPO-34, a material with acidic sites that help drive the reaction.

But when these materials are placed very close together, at the nanoscale, something unexpected happens. The metal ions can migrate and swap places with the acid sites in SAPO-34, changing how the reaction unfolds.

"People often think about how molecules move in these systems, but not how the metals themselves move," Shetty explained. "We're showing that these metals are not innocent bystanders. They move, and that movement has consequences."

Findings

The team found that indium ions tend to shut down the desired chemical pathways, leading mostly to methane, a less useful product in this context. Zinc ions, on the other hand, promote the formation of paraffins, which are more fuel-like. And chromium showed little interaction, allowing the reaction to proceed as intended.

"This research is about process intensification—making things more economical, using smaller reactors, saving on capital and operating costs," Shetty said. "But it's also about giving us control over what we make and how we make it."

As the researchers continue to refine their methods, they hope to offer practical solutions that transform scientific discovery into real-world application.

"This is just one step in a larger journey," Shetty said. "But it's a step that brings us closer to a more sustainable and economically resilient future."