Tracking the shape-dependent sintering of platinum-rhodium model catalysts under operando conditions

17Citations
Citations of this article
44Readers
Mendeley users who have this article in their library.

Abstract

Nanoparticle sintering during catalytic reactions is a major cause for catalyst deactivation. Understanding its atomic-scale processes and finding strategies to reduce it is of paramount scientific and economic interest. Here, we report on the composition-dependent three- dimensional restructuring of epitaxial platinum–rhodium alloy nanoparticles on alumina during carbon monoxide oxidation at 550K and near-atmospheric pressures employing in situ high-energy grazing incidence x-ray diffraction, online mass spectrometry and a combina- torial sample design. For platinum-rich particles our results disclose a dramatic reaction- induced height increase, accompanied by a corresponding reduction of the total particle surface coverage. We find this restructuring to be progressively reduced for particles with increasing rhodium composition. We explain our observations by a carbon monoxide oxi- dation promoted non-classical Ostwald ripening process during which smaller particles are destabilized by the heat of reaction. Its driving force lies in the initial particle shape which features for platinum-rich particles a kinetically stabilized, low aspect ratio.

Cite

CITATION STYLE

APA

Hejral, U., Müller, P., Balmes, O., Pontoni, D., & Stierle, A. (2016). Tracking the shape-dependent sintering of platinum-rhodium model catalysts under operando conditions. Nature Communications, 7. https://doi.org/10.1038/ncomms10964

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free