The Nobel Prize in Chemistry has been awarded to three scientists who created revolutionary porous materials that can collect water from desert air, capture carbon dioxide from industrial sites and remove toxins from water.
Susumu Kitagawa of Kyoto University, Richard Robson of the University of Melbourne and Omar Yagi of the University of California, Berkeley, shared the 11 million Swedish kronor (about £871,400) prize awarded by the Royal Swedish Academy of Sciences in Stockholm.
The trio found ways to combine metal ions and organic molecules into highly porous structures through which liquids and gases could flow. Since then, tens of thousands of such materials have been created for applications ranging from hydrogen storage to the permanent removal of chemicals from water and the extraction of valuable rare earth metals from waste.
The scientists were awarded “for the development of metal-organic frameworks,” or MOFs, which have such potential that they are being called the material of the 21st century.
Speaking at the prize ceremony, Professor Heiner Linke, Chairman of the Nobel Committee on Chemistry, said: “They have found ways to create materials, completely new materials with large cavities inside that can be seen almost like hotel rooms, so that guests' molecules can move in and out of the same material.
“A small amount of this material could be almost like Hermione's handbag in Harry Potter. It could store huge amounts of gas in a tiny volume.”
The research began in 1989 with Robson, a chemist born in Glassburn, West Yorkshire, who moved to Australia after studying at Oxford and Stanford universities. Inspired by the structure of diamonds, he combined copper ions with a four-armed molecule to create pyramid-shaped molecules. They joined together to form crystals dotted with cavities.
Robeson recognized the potential of these structures, but they were unstable and tended to fall apart. Further work was required by Kitagawa and Yagi to develop metal-organic frameworks into the valuable materials they are today.
Kitagawa showed that such structures based on cobalt, nickel and zinc are not only stable, but can also be used to store and release methane, nitrogen and oxygen. He further showed that MOFs can be adapted to different applications and can even be made from flexible materials.
Speaking to the Nobel Committee, Kitagawa said he was “deeply honored and delighted” to receive the prize. When asked about his hopes for the future, Kitagawa said he wants to use MOFs to extract important elements such as carbon and oxygen from the air and use green energy to turn them into useful materials. “This is my dream,” he said.
Yagi became interested in chemistry at the age of 10 after sneaking into the school library, which was usually locked, and taking a book at random from the shelves. He grew up with his siblings in one room in Amman, Jordan, without running water or electricity. At the insistence of his father, he went to study in the USA.
Disillusioned with the traditional way of creating new molecular structures, Yagi developed a more precise approach that was more like assembling Lego pieces into large crystals. In the 1990s, he discovered MOFs that resemble networks held together by copper or cobalt. Later he created an unusual MOF based on zinc. A couple of grams held an area the size of a football field, meaning it could absorb a huge amount of gas for its size.
Dr Becky Greenaway, a chemist at Imperial College London, said: “Many chemists have wondered when organometallic structures would win a Nobel Prize, and it has finally happened.
“Their discovery has enabled a range of applications, from gas storage and separation to drug delivery, and has also opened up other areas, including porous liquids—liquids with holes—that show promise in carbon capture and catalysis.”
