A schematic representation of the difference between structure sensitive and structure insensitive behavior of particles. Credit: Utrecht University.
A team of researchers has solved a fundamental mystery in catalysis. Researchers have been studying the optimal shape and size of the nanoparticles to make better catalysts. The shape and size of the nanoparticles did not seem to affect the performance of some catalysts. This is not true according to a research team led by Prof. Weckhuysen. The performance of these particles is always the same because they rearrange themselves quickly to an optimal structure. This insight can help in the development of catalysts for cleaner fuels.
The results of a team of researchers at Utrecht University, in collaboration with other institutions, were published in Nature Communications on December 7.
It was never truly explained.
Catalysts are used in the chemical industry to make fuels, chemicals and materials more efficient. Catalysts are small particles that work on their surface. Since catalyst particles are so small, their performance is highly dependent on their shape: A very small particle has more irregular surfaces with single atoms sticking out, while larger particles have more "flat" sides of atoms.
One would expect larger particles to behave differently than smaller ones, since they react differently on regular and irregular planes of atoms. There have been reactions where this does not occur. Charlotte Vogt is the first author of the paper.
Restructuring quickly.
The researchers used a combination of advanced instruments to study a set of nickel catalysts and compare their activity for a structure-insensitive reaction, turning ethene into ethane, and a structure-sensitive one: turning carbon dioxide into methane.
They observed a rapid surface restructuring of the metal. The restructuring happens faster for larger metal nanoparticles than for smaller ones. The metal surface rapidly changes as a function of particle size leaving only very specific sites exposed, which is the most likely explanation for structure insensitivity. The term "structure insensitivity" should be replaced by "apparent structure insensitivity."
Charlotte Vogt and her team have a paper on Dynamic restructuring of supported metal nanoparticles and its implications for structure-sensitive catalysis. There is a DOI titled " 10.1038/s41467-021-27474-3".
Nature Communications is a journal.
The mystery of'structure-insensitive' catalytic reactions was solved by researchers.
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