A new rule for catalyst design

The “ten electron rule” provides guidelines for the design of single-atom alloy catalysts for targeted chemical reactions.

A collaborative team from four universities has discovered a very simple rule for designing single-atom alloy catalysts for chemical reactions. The “ten electron rule” helps scientists very quickly identify promising catalysts for their experiments. Instead of numerous trial-and-error experiments of computationally demanding computer simulations, the composition of catalysts can be proposed simply by looking at the periodic table.

Monatomic alloys are a class of catalysts made up of two metals: a few atoms of a reactive metal, called a dopant, are diluted in an inert metal (copper, silver or gold). This recent technology is extremely effective in accelerating chemical reactions, but traditional models do not explain how they work.

The team, who worked at the University of Cambridge, University College London, the University of Oxford and Humboldt University Berlin, published their research in Natural chemistry. The scientists performed computer simulations to uncover the underlying laws that control the operation of single-atom alloy catalysts.

The rule showed a simple connection: chemicals bind most strongly to single-atom alloy catalysts when the dopant is surrounded by ten electrons. This means that scientists designing experiments can now simply use the columns of the periodic table to find which catalysts will have the desired properties for their reactions.

Dr Romain Réocreux, a postdoctoral researcher in Professor Angelos Michaelides’ group, who led this research, says: “When you have a difficult chemical reaction, you need a catalyst with optimal properties. The catalyst can poison and stop speeding up your reaction; on the other hand, a weakly bonded catalyst may simply do nothing. »

“We can now identify the optimal catalyst just by looking at a column in the periodic table. This is very powerful since the rule is simple and can accelerate the discovery of new catalysts for particularly difficult chemical reactions.”

Professor Stamatakis, Professor of Computational Inorganic Chemistry at the University of Oxford, who contributed to the research, said: “After a decade of intense research into single-atom alloys, we now have an elegant theoretical framework , simple but powerful that explains linking energy trends and allows us to make predictions about catalytic activity.

Using this rule, the team proposed a promising catalyst for an electrochemical version of the Haber-Bosch process, a key reaction for fertilizer synthesis that has used the same catalyst since its discovery in 1909.

Dr Julia Schumann, who started the project at the University of Cambridge and now works at Humboldt University in Berlin, explains: “Many catalysts used today in the chemical industry were discovered in the laboratory at using trial and error methods. material properties, we can offer new catalysts with improved energy efficiency and reduced CO emissions₂ emissions for industrial processes.