The Royal Swedish Academy of Sciences awarded the 2025 Nobel Prize in Chemistry to three scientists for their groundbreaking development of materials that can capture substances such as carbon dioxide or water vapor from the air. The laureates are Susumu Kitagawa of Kyoto University in Japan, Richard Robson of the University of Melbourne in Australia, and Omar M. Yaghi of the University of California, Berkeley. Their pioneering work on metal-organic frameworks, or MOFs, has created a new branch of chemistry, yielding highly porous materials with a vast range of applications aimed at solving some of humanity’s most pressing challenges.
Metal-organic frameworks are crystalline, sponge-like materials constructed from metal ions linked by organic molecules. This unique structure creates vast internal surface areas and cavities, allowing them to adsorb and store large quantities of gases and other molecules in a small volume. Members of the Nobel Committee likened the storage capacity of MOFs to the magical, space-expanding handbag from the “Harry Potter” series. The potential uses for these molecular constructions are extensive, including harvesting water from desert air, capturing industrial carbon emissions, storing fuel for clean-energy vehicles, and delivering pharmaceuticals within the human body. The academy recognized the trio for creating these molecular tools that offer previously unforeseen opportunities for custom-made materials.
A New Class of Porous Materials
The fundamental innovation recognized by the Nobel committee is the creation of a new class of solids with unprecedented porosity. MOFs are built by linking metal ions, which act as nodes, with organic molecules, which serve as struts. This methodical construction results in a rigid, three-dimensional framework with a highly ordered internal structure full of microscopic pores. The size and chemical properties of these pores can be precisely tailored by choosing different metal and organic components, allowing chemists to design MOFs for specific tasks.
The internal surface area of these materials is remarkably large. A small amount of a MOF, equivalent in volume to a sugar cube, can have an internal surface area comparable to a football field. This enormous capacity for adsorption is what makes them so powerful. Unlike other porous materials like zeolites or activated carbon, the structure of MOFs can be rationally designed and modified with a high degree of control. This allows for the creation of tens of thousands of different MOFs, each with unique properties tailored for absorbing, separating, or catalyzing specific molecules. This designability has opened a new frontier in materials science, giving researchers the ability to build materials for functions that were previously considered impossible.
Foundational Research and Key Discoveries
The development of metal-organic frameworks was not a single breakthrough but the result of sequential discoveries by the three laureates over more than a decade. The work began in 1989 when Richard Robson, then working largely alone, successfully combined positively charged copper atoms with a four-armed organic molecule to form a spacious, diamond-like crystal structure filled with countless tiny compartments. This laid the theoretical and practical groundwork for the field.
Building on the Foundation
Following Robson’s initial work, Omar Yaghi and Susumu Kitagawa independently advanced the field between 1992 and 2003. They demonstrated that gases could flow into and out of these frameworks without disrupting their structure. They also developed methods to make the frameworks more stable and flexible. In the early 2000s, Yaghi’s research group showed it was possible to rationally modify MOFs to alter their properties, producing 16 different versions of a framework known as MOF-5 with pores of varying sizes. One variant showed a remarkable ability to store large volumes of methane gas, suggesting future applications in natural gas-fueled vehicles. Kitagawa’s work focused on creating flexible frameworks whose pores could open and close in response to external stimuli, a property that allows for selective gas capture and release.
Applications in Energy and Environment
The most promising applications for MOFs are in addressing critical global challenges related to energy and the environment. Their exceptional ability to capture and store gases makes them ideal candidates for carbon capture and storage (CCS) technologies. Some MOFs, such as one known as CALF-20, have an exceptional capacity to absorb carbon dioxide and are already being tested at industrial facilities, including a cement plant in Canada. Cement manufacturing is a major source of global emissions, accounting for 7% of all carbon dioxide released into the atmosphere. By integrating MOFs into the manufacturing process, it becomes possible to capture CO2 before it is released, mitigating the industry’s climate impact.
Beyond carbon capture, MOFs are being developed for clean energy storage. Storing hydrogen safely and efficiently is a major obstacle to developing a hydrogen-based economy. The high porosity of MOFs allows them to store hydrogen gas at high densities under safer, lower-pressure conditions. Yaghi has suggested their use in vehicles fueled by renewable natural gas. Furthermore, these frameworks can be used to store other volatile chemicals or to break down toxic substances in the environment, such as traces of pharmaceuticals or antibiotics in water sources.
Harvesting Water and Purifying Resources
One of the most widely cited applications for metal-organic frameworks is the ability to harvest potable water directly from dry air. Professor Yaghi’s research group has developed MOFs that can efficiently absorb water vapor even in desert environments with low humidity. The captured water can then be released by applying a small amount of heat, providing a potential solution to water scarcity in arid regions around the world. These devices could offer a passive, low-energy method to produce drinking water where none was previously available.
The precise control over pore size also makes MOFs effective molecular sieves. They can be designed to separate specific molecules from complex mixtures, a function useful in a wide range of industrial and environmental processes. For example, some frameworks can trap ethylene gas produced by fruit, causing it to ripen more slowly and extending its shelf life. Others are being used experimentally to mine for rare-earth elements from wastewater or to remove harmful PFAS chemicals, also known as “forever chemicals,” from drinking water. This versatility positions MOFs as a key material for creating a more sustainable and resource-efficient future.
The International Laureates
The 11 million Swedish kronor ($1.2 million) prize is shared by three scientists from three different continents, reflecting the global nature of modern scientific research.
- Susumu Kitagawa, 74, is a professor at Kyoto University in Japan. Upon learning of the award, he stated that his dream is to use renewable energy to capture components of air and convert them into useful materials.
- Richard Robson is a professor at the University of Melbourne in Australia, where he has been a researcher and lecturer since 1966. He produced the first MOFs in the early 1990s and was noted for returning to work to teach a first-year chemistry tutorial hours after the Nobel announcement.
- Omar M. Yaghi, 60, is a professor at the University of California, Berkeley. Born in Jordan to a refugee family, he discovered a passion for chemistry after finding a book on molecules in a library at age 10 and has described science as “the greatest equalizing force in the world.”
The Nobel announcements for 2025 will conclude with the prize for economics, with the award ceremony scheduled for December 10, the anniversary of Alfred Nobel’s death.
