12/07/2021
Catalysis is at the heart of the solution of global challenges such as climate change. By using better, improved catalysts, industrial processes can run at lower temperatures, with higher selectivity and thereby saving energy and reducing the carbon footprint of consumer end products. Finding and improving heterogeneous catalysts has largely been a process of trial-and-error. This is about to change.
In a collaboration with colleagues from Tufts University and University College London we designed a novel single-atom-alloy (SAA) catalyst for the dehydrogenation of propane. Starting from a DFT-based screening study for C-H activation in methane, a single Rhodium atom dispersed in a Copper-metal host surface was identified as highly active and stable surface configuration. We found the single Rh atom to be as active as pure Pt in splitting the C-H bond of the fully saturated alkane, albeit with a decreased risk of being poisoned by coke, as subsequent dehydrogenation steps are less favourable.
Surface science experiments confirmed the successful formation of a RhCu-SAA single crystal surface and its small C-H activation barrier of methyl. In reactor studies with nanoparticle catalyst analogs of the RhCu model surface, the RhCu SAA proved to be more active and stable than a Pt catalyst for propane dehydrogenation to propene. These results were furthermore supported by DFT calculations.
This work presents a potential greener way for one of the largest scale industrial processes in the chemical industry, relevant for countless everyday items such as those from plastic and fabric manufacture. Our paper sets an example of the great potential of catalyst design guided by calculations from first principles.
Links:
https://science.sciencemag.org/content/372/6549/1444 (link to research article)
https://www.ucl.ac.uk/news/2021/jun/lowering-carbon-footprint-fabric-and-plastic-manufacturing
Image Credit: Michail Stamatakis, UCL