Scientists who pioneered a new class of materials with microscopic pores, leading to revolutionary applications from capturing carbon dioxide to harvesting water from arid air, have been awarded the 2025 Nobel Prize in Chemistry. The Royal Swedish Academy of Sciences in Stockholm awarded the prize to Susumu Kitagawa of Kyoto University, Richard Robson of the University of Melbourne, and Omar Yaghi of the University of California, Berkeley. The three laureates will share the 11 million Swedish kronor prize for their independent yet complementary discoveries in the design and synthesis of metal-organic frameworks, or MOFs.
These crystalline materials, composed of metal ions linked by organic molecules, form highly porous, three-dimensional structures with vast internal surface areas. A small MOF crystal, the size of a sugar cube, can have an internal surface area equivalent to a football pitch. This unique characteristic allows them to act like molecular sponges, capable of trapping, storing, and transporting gases and other small molecules with remarkable efficiency. The development of MOFs has opened up new frontiers in materials science, offering potential solutions to some of the world’s most pressing challenges, including climate change, water scarcity, and pollution.
The Genesis of a Molecular Architecture
The journey towards creating these revolutionary materials began in 1989 with the work of Richard Robson. At the University of Melbourne, Robson explored new ways of combining atoms, focusing on linking positively charged copper ions with a specially designed four-armed organic molecule. This innovative approach resulted in a well-ordered, spacious crystal structure. The Nobel Committee likened the creation to “a diamond filled with innumerable cavities.” Robson recognized the immense potential of this porous molecular construction. However, the initial frameworks he developed were unstable and had a tendency to collapse easily, a significant hurdle that limited their practical application. Despite this instability, Robson’s work laid the conceptual groundwork for a new type of chemistry, demonstrating that metal ions and organic linkers could be assembled into predictable, porous lattices.
Building on a Breakthrough
The full potential of Robson’s initial discovery was unlocked through the subsequent, independent work of Susumu Kitagawa and Omar Yaghi. Between 1992 and 2003, they made a series of revolutionary discoveries that transformed the field, providing the stability and functionality needed for MOFs to become a cornerstone of modern materials science.
Kitagawa’s Flexible Frameworks
Working at Kyoto University, Susumu Kitagawa made critical contributions to understanding the dynamic behavior of MOFs. He demonstrated that these porous structures were not rigid but could be designed to be flexible. Kitagawa showed that gases could flow in and out of the frameworks, and he predicted that this property could be controlled. This flexibility meant that the pores could open and close in response to external stimuli, allowing for selective gas adsorption and release. Kitagawa’s dream is to use MOFs to capture essential elements like carbon and oxygen from the air and, with the help of green energy, convert them into useful materials.
Yaghi’s Stable Structures and Rational Design
At the same time, Omar Yaghi, then at Arizona State University, was tackling the problem of stability. He succeeded in creating a very stable MOF, a zinc-based framework that did not collapse when the solvent molecules used in its creation were removed. This was a crucial step, proving that the porous “rooms” within the material could remain open and accessible. Yaghi further advanced the field by introducing the concept of “rational design.” He demonstrated that by carefully selecting the metal ions and organic linkers, chemists could precisely control the size of the pores and the properties of the resulting MOF. This ability to custom-build materials for specific tasks has been a driving force behind the explosion of research in the field.
A World of Tiny Sponges
The defining feature of MOFs is their extraordinary porosity. The internal cavities, or pores, are incredibly small, ranging from a few angstroms to several nanometers in width—far too small to be seen with the naked eye. These pores create an enormous internal surface area. Heiner Linke, Chair of the Nobel Committee for Chemistry, described the materials as being “almost like Hermione’s handbag in Harry Potter,” capable of storing huge amounts of gas in a tiny volume. This vast internal landscape provides a unique environment for chemical reactions and storage. The ability to trap and hold molecules makes MOFs ideal candidates for a wide range of applications that rely on molecular separation and containment.
From Theory to Transformative Applications
The discoveries of Kitagawa, Robson, and Yaghi have led to the creation of tens of thousands of different MOFs, each with unique properties tailored for specific functions. Researchers are now exploring a vast array of practical applications for these versatile materials.
Environmental Solutions
Many of the most promising applications for MOFs are in the environmental sector. Their ability to selectively capture gases makes them ideal for carbon capture technologies, separating carbon dioxide from industrial emissions at sources like cement plants. Another groundbreaking application is harvesting water from the air, even in arid desert environments, offering a potential solution to water scarcity. MOFs are also being developed to remove toxins from water, including per- and polyfluoroalkyl substances (PFAS), often called “forever chemicals,” and traces of pharmaceuticals.
Energy and Beyond
In the energy sector, MOFs offer a way to store fuels like hydrogen at high densities, which is a major challenge for the development of fuel-cell-powered vehicles. Their porous structure also makes them effective catalysts, providing a contained environment where chemical reactions can take place more efficiently. Beyond environmental and energy applications, researchers are exploring the use of MOFs in medicine for targeted drug delivery, in electronics, and as chemical sensors to detect contaminants.
The Future of Porous Materials
Despite being discovered over three decades ago, MOFs remain one of the most active areas of research in materials chemistry. The foundational work of the three Nobel laureates has provided chemists with a powerful toolkit for creating new materials with customized functions. As our understanding of how to design and synthesize MOFs grows, so does the list of potential applications. The versatility of these porous solids suggests they will continue to play a crucial role in addressing global challenges for many years to come. The Nobel Prize not only honors the pioneering work of Kitagawa, Robson, and Yaghi but also highlights the immense potential of this exciting field of chemistry.
The Laureates’ Journeys
The three scientists who shared the prize come from diverse backgrounds. Richard Robson was born in the UK in 1937 and is a professor at the University of Melbourne in Australia. Susumu Kitagawa is a distinguished professor at Kyoto University in Japan. Omar Yaghi was born in Amman, Jordan, in 1965 and is now a professor at the University of California, Berkeley. Yaghi, the first Nobel laureate born in Jordan, grew up in a family of Palestinian refugees in a home without electricity or running water. He has spoken about how science provides opportunities for talented people everywhere, calling it “the greatest equalizing force in the world.”
