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Title: The role of fluctuations in bistability and oscillations during the H{sub 2} + O{sub 2} reaction on nanosized rhodium crystals

A combined experimental and theoretical study is presented of fluctuations observed by field ion microscopy in the catalytic reaction of water production on a rhodium tip. A stochastic approach is developed to provide a comprehensive understanding of the different phenomena observed in the experiment, including burst noise manifesting itself in a bistability regime, noisy oscillations, and nanopatterns with a cross-like oxidized zone separating the surface into four quadrants centered on the (111) facets. The study is based on a stochastic model numerically simulating the processes of adsorption, desorption, reaction, and transport. The surface diffusion of hydrogen is described as a percolation process dominated by large clusters corresponding to the four quadrants. The model reproduces the observed phenomena in the ranges of temperature, pressures, and electric field of the experiment.
Authors:
;  [1] ;  [2]
  1. Center for Nonlinear Phenomena and Complex Systems (CENOLI), Université libre de Bruxelles (ULB), Campus Plaine Code Postal 231, B-1050 Brussels (Belgium)
  2. Center for Nonlinear Phenomena and Complex Systems (CENOLI) and Chemical Physics of Materials—Catalysis and Tribology, Université libre de Bruxelles (ULB), Campus Plaine Code Postal 243, B-1050 Brussels (Belgium)
Publication Date:
OSTI Identifier:
22493518
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 143; Journal Issue: 6; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ADSORPTION; CHEMICAL REACTIONS; CRYSTALS; DESORPTION; DIFFUSION; ELECTRIC FIELDS; FLUCTUATIONS; HYDROGEN; ION MICROSCOPY; NANOSTRUCTURES; NOISE; OSCILLATIONS; OXYGEN; RHODIUM; STOCHASTIC PROCESSES; SURFACES; WATER