A new X-ray method will enable the development of more efficient catalysts. The method opens up new opportunities to work on atomic level in a number of areas of materials science. Researchers from Lund University are among those behind the new method.
The new X-ray method is used to determine the atomic structure of the surface of different materials. The goal of the present research is to understand how catalysts work at atomic level - both the catalytic converters used for vehicle emissions control in cars and catalysts used in industry.
"Today, almost all developments in catalysts take place through a method of trial and error, but in order to be able to develop better catalysts in the future, deeper understanding of the atomic level is needed", says Dr Johan Gustafson, a researcher at the Department of Physics at Lund University.
A catalyst works by capturing the molecules that are to react on a catalytic surface. The effect of the surface on the molecules is to speed up the desired reaction. The surfaces of different materials capture and affect molecules in different ways. The new X-ray method offers researchers a significantly improved insight into what happens on these surfaces and in their active sites, i.e. the places where the molecules attach and react.
With this knowledge, the material in the catalyst can be optimised to speed up desired reactions and slow down others. The new X-ray method not only provides an instant picture of the situation on a surface, but can also be used to monitor changes over the time that the surface is subjected to different treatments.
"This could be a catalytic reaction that happens on the surface, as in our case. But it would also be possible to monitor how nanostructures grow or how metals oxidise, in conjunction with corrosion, as protection against corrosion or to change the properties of the surface in another way", says Johan Gustafson.
The researchers have developed the new X-ray method by using X-rays of around five times higher energy than usual. This means that a larger amount of data can be measured simultaneously, which in turn drastically reduces the time taken to conduct a full surface structure determination, from ten hours with the traditional method to roughly ten minutes with the new method.
The journal Science now reports on the new X-ray method, which Johan Gustafson has developed with colleagues from Lund University, Chalmers University of Technology in Gothenburg, the DESY research centre in Germany and Hamburg University.