Nobel laureate Omar Yaghi says his invention will change the world

Civilizations name their ages after materials. In school we learn about the Stone Age, the Bronze Age – and we are currently in the Silicon Age, characterized by computers and telephones. What can define the next age? Omar Yaghi at the University of California, Berkeley, thinks the family of materials he helped pioneer in the 1990s has a good chance. They are metal-organic frameworks (MOFs), and the solution to how to make them has earned him a share of the 2025 Nobel Prize in Chemistry.

MOFs and their related covalent organic frameworks (COFs) are crystalline materials, but what sets them apart is their incredible porosity. In 1999, Yaghi and his colleagues made a splash when they synthesized a zinc-based material called MOF-5 that was so riddled with pores that a few grams of it had an interior surface comparable to a football field (see image below). The inside of the material was actually much larger than its outside.

For decades, Yaghi has been at the forefront of making new MOFs and COFs, a discipline known as reticular chemistry, and working to see how useful they can be. Because other molecules can be drawn into the rich pores of these materials, they have proven to be great at extracting water from dry desert air, absorbing carbon dioxide from the atmosphere, and much more. Yaghi spoke The new scientist about why he’s optimistic about the work, the past, present and future of reticular chemistry—and why he thinks the age of these materials is dawning.

Karmela Padavic-Callaghan: What initially attracted you to reticular chemistry?

Omar Yaghi: When we started working with MF, we didn’t think we were going to solve social challenges – it was an intellectual challenge. We wanted to find a way to make materials one molecule at a time, like building a building or programming molecules like Lego. But this was a truly formidable chemical challenge. For many people it was taken as an article of faith that it wouldn’t work, that pursuing it was a waste of time.

Why did designing materials in this way seem so impossible?

The main problem with building materials in a rational way is that usually when you mix chemical building blocks, you end up joining them together in a way that is messy and hard to describe. This is not surprising given the laws of physics which tell us that nature tends towards high entropy or disorder. Instead, we wanted to end up with crystals, with ordered matter that has a repeating, periodic structure.

It’s a bit like asking a room of children to make a perfect circle: it takes hard work, and when they do, they can still separate their hands, or “disconnect” their hands, and then take too long to complete the circle again. In other words, we tried to do what nature does when it crystallizes diamonds over billions of years – but in a day. But deep down I knew that anything can be crystallized if you know how.

THEIn 1999, your instincts proved correct and your team reported on it synthesis of MOF-5which was unprecedentedly stable. Did you consider that such material might become useful over time?

We identified a solvent that could help synthesize a stable MOF, and then we were able to understand how it works. We realized that having his molecules in the mix was absolutely critical to modulating the propensity for disorder. Since then, this method has been used by thousands of researchers.

In the beginning I was just excited about making beautiful crystals. Then we saw their great features and were able to say, “Wow, what can we do with this?” And once you know the porosity of these materials, you immediately think about trapping gases. These materials include areas of space where a molecule of water or carbon dioxide or something else can sit.

Tell me about how you think about making these materials today.

When I cook, I don’t like to do more than three steps and not use butter. So the challenge is how to get a masterful meal in so few steps and using only healthy ingredients. This philosophy spilled over into my chemistry. In other words, I want to keep the process simple and only use the chemicals we actually need.

The first step is to choose the backbone of the material. The second is deciding on the size of its pores. You can also perform chemistry on the skeleton and add molecules to it to help trap other compounds into the pores. The third step is to inhale the carbon dioxide or whatever you have created from the material. This is how easy the process is and how complicated it is.

What kind of new technologies has this process made possible for you?

Once you learn how to design materials at the molecular level, that’s the ultimate achievement, a geological shift. My vision and the vision of the company I founded in 2020, Atocois to go from the molecule to the society, look at the places where the material is not for a task or does it, and then rationally design a better wrong. As we improve in the production of materials, we improve social standards.

In 2024, we reported on the best carbon dioxide capture material to date, the so-called COF-999. It captures from the air and we tested it for over 100 capture cycles [expelling] carbon dioxide here in Berkeley. Atoco aims to use reticular materials such as COF-999 to build carbon capture modules that could work in industrial environments as well as residential buildings.

We have also developed materials that can capture thousands of liters of water per day from the atmosphere. This is the basis for our devices, which can extract water vapor from the air even in places where the humidity is below 20 percent, such as the desert regions of Nevada. I think that in 10 years water harvesting will be an everyday technology.

There are other technologies that can capture water, such as devices that condense atmospheric vapors, and there are other devices that can also capture CO2. How do MOFs and COFs compare?

We have so much control over the chemistry that we can manufacture our devices sustainably. They could work for many, many years, and at the end of the MOF part of the device, you can disassemble it in water so that no MOF escapes into the environment. So in a world where MOFs are scaled to the multi-ton level and used in many different applications, we will not face the “MOF waste problem”.

And these devices can be much more energy efficient because, for example, we’ve figured out how to use ambient sunlight to make water harvesters release water. We could also use waste heat from industrial processes for carbon capture devices [to get them to release CO2]which would make them more economical and sustainable than competing technologies.

However, there are still scalability issues to make the materials chemically stable and to have precise control over how and when they release the molecules they absorb from the environment. For example, we can already produce MOFs on a ton scale, but we cannot yet produce COFs in such large quantities. In a few years, I suspect that we will go to larger dimensions. As another example, for even better water capture, we need to optimize how the materials hold on to water – it can’t be too strong or too weak.

We also now use AI agents to help optimize MOFs and COFs and make the design process as efficient as possible. In general, it is easy to make a MOF or COF, but it can take a year to create one with specifically optimized properties. If an AI agent can do this faster, that would be transformational. I went into the lab and told everyone to try using large language models, and we’ve already doubled the speed at which we can create some new MOFs.

What are the uses of reticular chemistry that you think more people should be excited about?

Reticular chemistry is currently a massive field: millions of new MOFs can still be made, and chemists are a bit like kids in a candy store. One attractive idea is to use MOFs to do what enzymes do when they speed up chemical reactions, a process called catalysis, which can help synthesize useful chemicals, such as in drug development. We have MOFs that can do what enzymes do, but could last and work longer than enzymes. This is ripe for use for biological applications, for therapeutics, in the next decade or so.

But I think the next best use cases will come from “multivariate materials,” which is research you don’t hear much about because it only happens in my lab. Here we want to create MOFs that do not have the same structure through and through, but have significantly different environments within them. We can make them out of different modules that are “decorated” with different compounds, so there would be very different microenvironments inside the material that would make specific molecules do specific things. We have already been able to use this in experiments to produce materials that absorb gases more selectively and efficiently. This is also a shift in the thinking of chemists. Chemists are not used to thinking about making heterogeneous or non-uniform materials, but we want a very ordered framework for a material combined with very heterogeneous interiors.

What makes you optimistic about the future of MOF and COF? “Miracle Materials” have come and gone before.

We’ve only scratched the surface here, and we’re not short of ideas. Since the 1990s, the field has been expanding. Often research interests decline over time, but that didn’t happen here, and if you look at the growth of patents related to MOFs and COFs, you see an exponential increase there as well. People continue to see ways to not only solve intellectual problems in chemistry, but to find new applications and uses for these materials. And I like how this work combines organic and inorganic chemistry into one field, and now brings in engineering and artificial intelligence as well. It has become more than chemistry: this type of research is a true scientific frontier.

I think we are going through a revolution. It doesn’t always seem like it, but something strange is happening. We can design materials like never before and connect them to uses like never before.

topics:

• chemistry /
• materials science