• The Lindlar catalyst plays an important role in many chemical syntheses and especially in the life science industry.
• ISIS has enabled catalyst researchers at Evonik Industries to understand exactly how the widely used Lindlar catalyst, which the company makes and supplies to a range of industrial customers, works at the atomic scale.
• As well as aiding future catalyst development and optimisation, this understanding  will help the company increase market share by convincing customers that it has the knowledge to maximise the catalyst’s effectiveness and avoid operational problems in new applications.

The Lindlar catalyst, which incorporates the metals palladium and lead, is used in the commercial manufacture of vitamins and a range of other applications. In chemical terms, the catalyst enables hydrogen atoms to be added to alkynes to turn them into alkenes, while preventing further reactions that would result in the alkenes then turning into unreactive and unwanted alkanes.

Both the palladium and the lead play key roles. The palladium splits the molecules in hydrogen gas into the separate hydrogen atoms needed for alkene production, while the lead enables the catalyst to stop the reaction at the required point. Evonik Industries, a manufacturer of Lindlar and many other catalysts, wanted to reinforce the scientific base and acquire a competitive edge by developing a unique understanding of the Lindlar catalyst and, in particular, of why its behaviour at the nanoscale enables it to function as it does.

Having proved that the palladium and lead in the Lindlar catalyst form a genuine alloy at atomic level, AQura GmbH (Evonik Industries’ central analytical service provider) turned to ISIS to use its state-of-the-art neutron scattering capabilities to shed light on what exactly happens on the surface of the catalyst during a chemical reaction.

“Using the Maps instrument, our experiments revealed that the presence of lead in the alloy reduces the amount of hydrogen that the catalyst can physically hold inside the alloy particles,” says Dr Stewart Parker of ISIS. “With less hydrogen available, the reaction therefore stops at an earlier stage than would be the case if the catalyst didn’t incorporate lead.”

“The results generated by ISIS provided us with the missing piece of the jigsaw”, says Dr Peter Albers of AQura GmbH. “We now know precisely how the Lindlar catalyst behaves and why it is so effective at preventing alkane production. Our collaboration with ISIS has resulted in new knowledge that will translate directly into a higher-quality, more comprehensive service for our industrial customers.” 

“This case study impressively demonstrates that applying new analytical methods is one key step to understanding the critical parameters that control the performance of a catalyst,” says Dr Konrad Möbus, Technical Manager at Evonik Industries. “This will help us to improve further o​ur industrial catalysts for the benefit of our customers.”

 

Inside ISIS Target Station 1. South side view of the hall with the green Maps instrument in the foreground.

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Barry Hague

Research date: July 2012

Further Information

For more information about catalyst research at ISIS, contact Dr Stewart Parker