To break or not to break? A close look on how catalyst material converts harmful exhaust
For the foreseeable future, combustion engines will still play a large role in transport applications. To convert their toxic NOx exhaust into harmless gases, efficient catalysts are needed.
A Japanese-Dutch team zoomed into the functional bottleneck of these catalyst: the cleavage of the NO molecule’s bond after adsorption on the catalyst surface. Using metal cluster model systems for such catalysts and varying their elemental composition, the team employed the free-electron laser FELIX and quantum-chemical calculations to identify the metal cluster’s love for oxygen atoms as the key property determining whether NO was cleaved after adsorption or not.
Figure: correlation between the binding energy and perceived NO dissociation.
Although optimizing catalysts for the overall NO reduction reaction will certainly require more descriptors, employing the oxophilicity of adsorption sites could become an important figure of merit for the design of tailored NO reduction catalysts.
Reference
Oxophilicity as a Descriptor for NO Cleavage Efficiency over Group IX Metal Clusters, Masato Yamaguchi, Yufei Zhang, Satoshi Kudoh, Kohei Koyama, Olga V. Lushchikova, Joost M. Bakker and Fumitaka Mafuné, Journal of Physical Chemistry Letters 11, 4408–4412 (2020)
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Joost Bakker