Open AccessNanometric chemical clocks
Author(s) -
JeanSabin McEwen,
Pierre Gaspard,
Thierry Visart de Bocarmé,
Norbert Kruse
Publication year - 2009
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.0811941106
Subject(s) - nanoreactor , chemical physics , non equilibrium thermodynamics , nanoscopic scale , crystal (programming language) , anisotropy , catalysis , diffusion , field ion microscope , materials science , nanotechnology , chemical species , chemical reaction , hydrogen , ion , chemistry , nanoparticle , physics , thermodynamics , optics , biochemistry , organic chemistry , computer science , programming language
Field ion microscopy combined with video techniques and chemical probing reveals the existence of catalytic oscillatory patterns at the nanoscale. This is the case when a rhodium nanosized crystal--conditioned as a field emitter tip--is exposed to hydrogen and oxygen. Here, we show that these nonequilibrium oscillatory patterns find their origin in the different catalytic properties of all of the nanofacets that are simultaneously exposed at the tip's surface. These results suggest that the underlying surface anisotropy, rather than a standard reaction-diffusion mechanism, plays a major role in determining the self-organizational behavior of multifaceted nanostructured surfaces. Surprisingly, this nanoreactor, composed of the tip crystal and a constant molecular flow of reactants, is large enough for the emergence of regular oscillations from the molecular fluctuations.