Using the apex of a Rh-nanotip as model of a single catalytic particle and field emission microscopy (FEM) as imaging tool, ongoing catalytic reactions can be visualized on a nm-scale. In this way, H₂ oxidation on Rh in a specific mode, in which the reaction oscillates in a self-sustained way without external stimulus, was in situ imaged and new atomistic details were revealed. An original sophisticated method for tracking nm-sized instabilities in surface processes allowed the identification of local nano-pacemakers which initiate kinetic transitions and the nucleation of reaction fronts. The pacemakers turned out to be specific surface atomic configurations at the border between strongly corrugated Rh{973} regions and adjacent atomically flat terraces. These novel insights into the initiation and propagation of kinetic transitions on a single catalytic nanoparticle demonstrate how in situ monitoring of an ongoing reaction on individual nanofacets of a catalytic particle can single out active configurations, opening new ways for targeted tailoring of future catalysts.

Original publication:

Single particle catalysis: revealing intraparticle pacemakers in catalytic H₂ oxidation on Rh

J. Zeininger, Y. Suchorski, M. Raab, S. Buhr, H. Grönbeck, G. Rupprechter

ACS Catalysis, 11 (2021) 10020–10027

doi.org/10.1021/acscatal.1c02384, opens an external URL in a new window

Die Arbeiten wurden im Rahmen des vom FWF geförderten Projekts „Spatial-temporal phenomenaon surface structure libraries“ durchgeführt.