When experimental results don't match scientists' predictions, it's usually assumed the predictions were wrong. But new research into materials that pull carbon dioxide directly from the air shows how such mismatches can instead be powerful clues, leading to discoveries that reshape how future materials are designed.
In a paper published Dec. 21 in the Journal of the American Chemical Society (JACS) , a team led by Prof. Laura Gagliardi of the UChicago Pritzker School of Molecular Engineering (UChicago PME) and Department of Chemistry and Nobel laureate Prof. Omar Yaghi of the University of California, Berkeley outlined a new method for excluding water when using covalent organic frameworks (COFs) to build carbon capture materials.
In recognition of the scientific importance and real-world impact of this research, JACS selected the paper as its "Editor's Choice."
"Mismatches between simulations and experiments are not failures, but opportunities," said first author Hilal Daglar, who conducted the work as a postdoctoral researcher in Gagliardi's lab and is now with UL Research Institutes. "In this project, those discrepancies guided us toward residual water and subtle structural features that were not obvious at first glance."
The work came from The Center for Advanced Materials for Environmental Solutions (CAMES), which Gagliardi co-directs as part of the University of Chicago Institute for Climate & Sustainable Growth . By outlining a design strategy where researchers introduce hydrophobic pore environments to exclude retained water, the research will allow scientists to create more effective and efficient solutions for air pollution.
"We think of CAMES as a bridge between materials discovered in the lab and real-world environmental impact," said CAMES Co-Director Doug Weinberg. "Our role isn't just to support breakthrough science. It's to help ensure those breakthroughs matter beyond the lab. Hilal's work is a great example of that mission in action."
Exploring the mystery
Gagliardi has studied the power and potential of COFs and reticular chemistry for the last ten years, but COFs were thrust into the public eye this year after Gagliardi's longtime collaborator Yaghi won the 2025 Nobel Prize in Chemistry alongside Susumu Kitagawa and Richard Robson.
"These materials are known as reticular frameworks, meaning they are built from well-defined molecular building blocks that are connected through strong chemical bonds into extended crystalline networks," Gagliardi said. "Because the connectivity is designed at the molecular level, these frameworks contain uniform, nanoscale pores, giving them exceptionally large internal surface areas that can be deliberately functionalized for specific applications."
By using those large cavities to capture and store airborne pollutants like carbon dioxide and methane, Gagliardi and her team hope to use these materials' unique properties for this major environmental issue.
Harnessing Gagliardi's theoretical modeling expertise, Daglar and Gagliardi performed complex computer simulations predicting the structure of COF-999-NH2, the precursor of COF-999, a promising material for CO2 capture from air. But there was a disconnect between their predictions and the results produced by the experimentalists on Yaghi's team.
Rather than assume failure of the computations, the theorists and experimentalists dove into this mystery together, coming up with new, unexpected insights.
"In this back and forth between experiment and theory, we started to hypothesize that there were some residual water molecules in the synthesized material, which we initially did not include in our model because the experimentalists thought that the material had been completely dehydrated," Gagliardi said.
New insights, new rule
This investigation led not only to new insights into the cause of this predictive mismatch, but a path to better, more effective carbon capture in the future. They created a simple, actionable design rule for future researchers: controlling the pore hydrophobicity during the polymerization of COF-999 avoids water retention.
"This prevents adsorption site blockage and undesired side reactions, enabling more effective carbon capture," Daglar said.
Beyond this core finding, the research also revealed previously unknown insights about COFs, including that the stacking heterogeneity, buckling and lattice contraction they were seeing were features, not bugs, intrinsic to their precursor chemical.
Gagliardi said the emergence of these important results from predictions that conflicted with experiment underscores the central role of computational modeling in enabling the research.
"To advance these discoveries, computations and simulations are indispensable," she said. "On the computer, you can try things that maybe your chemical intuition might not suggest right away. The computer can give you some useful answers that allow you to think in a different way."
Citation: "Discovery of Stacking Heterogeneity Layer Buckling and Residual Water in COF-999-NH2 and Implications on CO2 Capture," Daglar et al, Journal of the American Chemical Society, December 21, 2025. DOI: 10.1021/jacs.5c18608
