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Cracking Metal To Atoms For More Sustainable Catalysts
January 4, 2022 | Leave a Comment
University of Nottingham scientists have discovered a new process to break bulk metal into atoms to produce heterogeneous catalysts without any chemical waste. Its a technique that will lead to new sustainable ways of making and using molecules in the most atom efficient way.
Researchers from the University of Nottingham have demonstrated that “naked” Pt atoms can be dispersed onto powder supports directly by splitting bulk metal to atoms at the record-breaking rate of four and a half thousand trillion atoms per second (4.5 x 1015 atom/s) by magnetron sputtering. The method is scalable and solvent-free and opens the door for fabrication of valuable catalyst materials where platinum (Pt) atoms are supported on powder particles.
Catalysts enable nearly 80% of industrial chemical processes that deliver the most vital ingredients of our economy, from materials (such as polymers) and pharmaceuticals to agrochemicals including fertilizers and crop protection.
The high demand for catalysts means that global supplies of many useful metals, including gold, platinum and palladium, are becoming rapidly depleted.
To protect these metal supplies it is vital to utilize each and every atom to its maximum potential. Atomic dispersion of metals in the support materials is one of the most powerful strategies for increasing the active surface area available for catalysis. The properties of the metal atoms can change drastically when compared with metal nanoparticles, leading to new phenomena otherwise inaccessible at the macroscale.
Traditionally methods for the preparation of atomically dispersed metal catalysts are based on either wet-chemistry (i.e reduction of metal salts) or atomic layer deposition (ALD). Industrial scale-up of these methods is difficult because they require multiple steps and/or high temperatures, generate large amounts of chemical waste, and are not readily generalizable across supports and metal catalysts.
This new research demonstrates how magnetron sputtering enables the production of atomically dispersed metals, including platinum, cobalt and nickel described in the current publication, in any support material in a sustainable and scalable fashion. This method has been used in the glasscoating and semiconductors industry, and has now been adapted to make atomically dispersed metal catalysts.
The research team used analytical and imaging techniques to demonstrate the Pt atoms were atomically dispersed over the entire surface of the powder support and then applied this catalyst for photocatalytic hydrogen production.
Dr. Jesum Alves Fernandes, Assistant Professor in Chemistry at University of Nottingham, who led the research said, “At the heart of our method individual metal atoms are knocked out of the bulk metal one by one by a fast beam of argon ions creating a shower of metal atoms raining onto the support material. The desired quantity of metal atoms can be generated on demand within seconds, but controlling their distribution on the powder support still remains a challenge. We are making good progress with designing innovative mixing systems for magnetron sputtering process and filed for a patent earlier this year.”
The University of Nottingham leads a large-scale interdisciplinary project, in collaboration with Universities of Cardiff, Birmingham and Cambridge, to expand on this work called ‘Metal Atoms on Surfaces & Interfaces (MASI) for Sustainable Future’. The project is funded by the Engineering & Physical Sciences Research Council (EPSRC), an effort launched in August 2021.
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It does look like this technology has the qualities to go to market and save a lot of material and money. Catalysts are critical across the whole of the food and fuel production process. This might be an unsung, but immensely important body of work. Congratulations are sincerely sent.