Emergence of chaos in a compartmentalized catalytic reaction nanosystem

Abstract

In compartmentalized systems, chemical reactions may proceed in differing ways even in adjacent compartments. In compartmentalized nanosystems, the reaction behaviour may deviate from that observed on the macro- or mesoscale. In situ studies of processes in such nanosystems meet severe experimental challenges, often leaving the field to theoretical simulations. Here, a rhodium nanocrystal surface consisting of different nm-sized nanofacets is used as a model of a compartmentalized reaction nanosystem. Using field emission microscopy, different reaction modes are observed, including a transition to spatio-temporal chaos. The transitions between different modes are caused by variations of the hydrogen pressure modifying the strength of diffusive coupling between individual nanofacets. Microkinetic simulations, performed for a network of 52 coupled oscillators, reveal the origins of the different reaction modes. Since diffusive coupling is characteristic for many living and non-living compartmentalized systems, the current findings may be relevant for a wide class of reaction systems.

Spin-mediated promotion of Co catalysts for ammonia synthesis

“…Above all, on this volcano-like dependence curve of apparent activity on La coverage, activity on the left leg is limited by the La coverage, whereas that on the right leg is hampered by the insufficient number of Co B 5 sites. A medium coverage of La as a promotor on a rhodium (Rh) surface for an optimized performance toward hydrogen oxidation reaction was reported recently (26).…”

Imaging Interface and Particle Size Effects by In Situ Correlative Microscopy of a Catalytic Reaction

“…XPEEM alone can already provide correlative spectroscopic data and microscopy images, but its capabilities are limited in terms of spectroscopy of sub-micrometer areas and imaging areas larger than several micrometers. , Thus, a combination with other techniques is often beneficial. Apart from the known steady states of high and low activity and bistability, − previous studies shed light on the spatio-temporal phenomena in catalytic H 2 oxidation on Rh, including mono- and multi-frequential self-sustaining oscillations, ,, coexisting multi-states, or the emergence of chaos . For supported Rh particles, such an approach has not yet been applied.…”

“…Apart from the known steady states of high and low activity and bistability, 41 − 44 previous studies shed light on the spatio-temporal phenomena in catalytic H 2 oxidation on Rh, including mono- and multi-frequential self-sustaining oscillations, 12 , 45 , 46 coexisting multi-states, 47 or the emergence of chaos. 48 For supported Rh particles, such an approach has not yet been applied. Based on the thorough understanding of the mechanism of hydrogen oxidation, it can be used as a test reaction to probe catalytically inactive and active states.…”

Dynamic chaos of imaging measurements for characterizing gas–liquid nonlinear flow behaviour in a metallurgical reactor stirred by top‐blown air

“…[ 19 ] Chaos, which is an important development of nonlinear time series analysis, has been widely found in biology, [ 20,21 ] medicine, [ 22 ] finance, [ 23 ] industrial, [ 24,25 ] and other research areas. [ 26–28 ] It has been confirmed that chaotic phenomena exist not only in the aforementioned kinds of systems, but also in various fluids mixing systems. For instance, Ghayesh et al studied the effect of flow pulsations on chaos in nanotubes using nonlocal strain gradient theory.…”